diff --git a/common/proto/exchange_rates.proto b/common/proto/exchange_rates.proto
index 72ecd709..3234b96e 100644
--- a/common/proto/exchange_rates.proto
+++ b/common/proto/exchange_rates.proto
@@ -2,6 +2,8 @@ syntax = "proto3";
 
 package komp_ac.exchange_rates;
 
+import "common.proto";
+
 // Selects WHICH DATE supplies the rate; this is independent of where the rate
 // comes from. These are not four user-facing choices: UNSPECIFIED is protobuf's
 // zero-value sentinel and is rejected when an explicit selection is supplied.
@@ -67,6 +69,10 @@ message ExchangeRateSelection {
 }
 
 service ExchangeRateService {
+  // Lists the direct-rate providers compiled into and registered by this
+  // server instance. Clients use these stable IDs when configuring profiles.
+  rpc ListRateSources(komp_ac.common.Empty)
+      returns (ListRateSourcesResponse);
   rpc PreviewDirectConversion(PreviewDirectConversionRequest)
       returns (PreviewDirectConversionResponse);
   rpc ListConversionEvidence(ListConversionEvidenceRequest)
@@ -77,6 +83,14 @@ service ExchangeRateService {
       returns (ProfileForeignCurrency);
 }
 
+message RateSourceProvider {
+  string id = 1;
+}
+
+message ListRateSourcesResponse {
+  repeated RateSourceProvider sources = 1;
+}
+
 message PreviewDirectConversionRequest {
   string original_amount = 1;
   string original_currency = 2;
diff --git a/common/proto/table_definition.proto b/common/proto/table_definition.proto
index 076a1873..31a9fd16 100644
--- a/common/proto/table_definition.proto
+++ b/common/proto/table_definition.proto
@@ -443,6 +443,11 @@ message TableDetail {
   // requested profile when a global table is being listed. See
   // ProfileTreeResponse.Table.profile_name.
   string profile_name = 11;
+
+  // True when the physical table contains at least one row, including a
+  // soft-deleted row. Populated tables are append-only: PutTableDefinition is
+  // no longer available, while AddTableColumns remains available.
+  bool has_data = 12;
 }
 
 // Server-owned behavior for one logical column returned in table details.
diff --git a/common/src/proto/descriptor.bin b/common/src/proto/descriptor.bin
index f45b2ca7..a71ec3ae 100644
Binary files a/common/src/proto/descriptor.bin and b/common/src/proto/descriptor.bin differ
diff --git a/common/src/proto/komp_ac.exchange_rates.rs b/common/src/proto/komp_ac.exchange_rates.rs
index d3d48a46..64ed3319 100644
--- a/common/src/proto/komp_ac.exchange_rates.rs
+++ b/common/src/proto/komp_ac.exchange_rates.rs
@@ -18,6 +18,16 @@ pub struct ExchangeRateSelection {
     pub rate_source_id: ::core::option::Option<::prost::alloc::string::String>,
 }
 #[derive(Clone, PartialEq, Eq, Hash, ::prost::Message)]
+pub struct RateSourceProvider {
+    #[prost(string, tag = "1")]
+    pub id: ::prost::alloc::string::String,
+}
+#[derive(Clone, PartialEq, ::prost::Message)]
+pub struct ListRateSourcesResponse {
+    #[prost(message, repeated, tag = "1")]
+    pub sources: ::prost::alloc::vec::Vec<RateSourceProvider>,
+}
+#[derive(Clone, PartialEq, Eq, Hash, ::prost::Message)]
 pub struct PreviewDirectConversionRequest {
     #[prost(string, tag = "1")]
     pub original_amount: ::prost::alloc::string::String,
@@ -408,6 +418,37 @@ pub mod exchange_rate_service_client {
             self.inner = self.inner.max_encoding_message_size(limit);
             self
         }
+        /// Lists the direct-rate providers compiled into and registered by this
+        /// server instance. Clients use these stable IDs when configuring profiles.
+        pub async fn list_rate_sources(
+            &mut self,
+            request: impl tonic::IntoRequest<super::super::common::Empty>,
+        ) -> std::result::Result<
+            tonic::Response<super::ListRateSourcesResponse>,
+            tonic::Status,
+        > {
+            self.inner
+                .ready()
+                .await
+                .map_err(|e| {
+                    tonic::Status::unknown(
+                        format!("Service was not ready: {}", e.into()),
+                    )
+                })?;
+            let codec = tonic_prost::ProstCodec::default();
+            let path = http::uri::PathAndQuery::from_static(
+                "/komp_ac.exchange_rates.ExchangeRateService/ListRateSources",
+            );
+            let mut req = request.into_request();
+            req.extensions_mut()
+                .insert(
+                    GrpcMethod::new(
+                        "komp_ac.exchange_rates.ExchangeRateService",
+                        "ListRateSources",
+                    ),
+                );
+            self.inner.unary(req, path, codec).await
+        }
         pub async fn preview_direct_conversion(
             &mut self,
             request: impl tonic::IntoRequest<super::PreviewDirectConversionRequest>,
@@ -541,6 +582,15 @@ pub mod exchange_rate_service_server {
     /// Generated trait containing gRPC methods that should be implemented for use with ExchangeRateServiceServer.
     #[async_trait]
     pub trait ExchangeRateService: std::marker::Send + std::marker::Sync + 'static {
+        /// Lists the direct-rate providers compiled into and registered by this
+        /// server instance. Clients use these stable IDs when configuring profiles.
+        async fn list_rate_sources(
+            &self,
+            request: tonic::Request<super::super::common::Empty>,
+        ) -> std::result::Result<
+            tonic::Response<super::ListRateSourcesResponse>,
+            tonic::Status,
+        >;
         async fn preview_direct_conversion(
             &self,
             request: tonic::Request<super::PreviewDirectConversionRequest>,
@@ -646,6 +696,55 @@ pub mod exchange_rate_service_server {
         }
         fn call(&mut self, req: http::Request<B>) -> Self::Future {
             match req.uri().path() {
+                "/komp_ac.exchange_rates.ExchangeRateService/ListRateSources" => {
+                    #[allow(non_camel_case_types)]
+                    struct ListRateSourcesSvc<T: ExchangeRateService>(pub Arc<T>);
+                    impl<
+                        T: ExchangeRateService,
+                    > tonic::server::UnaryService<super::super::common::Empty>
+                    for ListRateSourcesSvc<T> {
+                        type Response = super::ListRateSourcesResponse;
+                        type Future = BoxFuture<
+                            tonic::Response<Self::Response>,
+                            tonic::Status,
+                        >;
+                        fn call(
+                            &mut self,
+                            request: tonic::Request<super::super::common::Empty>,
+                        ) -> Self::Future {
+                            let inner = Arc::clone(&self.0);
+                            let fut = async move {
+                                <T as ExchangeRateService>::list_rate_sources(
+                                        &inner,
+                                        request,
+                                    )
+                                    .await
+                            };
+                            Box::pin(fut)
+                        }
+                    }
+                    let accept_compression_encodings = self.accept_compression_encodings;
+                    let send_compression_encodings = self.send_compression_encodings;
+                    let max_decoding_message_size = self.max_decoding_message_size;
+                    let max_encoding_message_size = self.max_encoding_message_size;
+                    let inner = self.inner.clone();
+                    let fut = async move {
+                        let method = ListRateSourcesSvc(inner);
+                        let codec = tonic_prost::ProstCodec::default();
+                        let mut grpc = tonic::server::Grpc::new(codec)
+                            .apply_compression_config(
+                                accept_compression_encodings,
+                                send_compression_encodings,
+                            )
+                            .apply_max_message_size_config(
+                                max_decoding_message_size,
+                                max_encoding_message_size,
+                            );
+                        let res = grpc.unary(method, req).await;
+                        Ok(res)
+                    };
+                    Box::pin(fut)
+                }
                 "/komp_ac.exchange_rates.ExchangeRateService/PreviewDirectConversion" => {
                     #[allow(non_camel_case_types)]
                     struct PreviewDirectConversionSvc<T: ExchangeRateService>(
diff --git a/common/src/proto/komp_ac.table_definition.rs b/common/src/proto/komp_ac.table_definition.rs
index 2d84a993..7a498dba 100644
--- a/common/src/proto/komp_ac.table_definition.rs
+++ b/common/src/proto/komp_ac.table_definition.rs
@@ -458,6 +458,11 @@ pub struct TableDetail {
     /// ProfileTreeResponse.Table.profile_name.
     #[prost(string, tag = "11")]
     pub profile_name: ::prost::alloc::string::String,
+    /// True when the physical table contains at least one row, including a
+    /// soft-deleted row. Populated tables are append-only: PutTableDefinition is
+    /// no longer available, while AddTableColumns remains available.
+    #[prost(bool, tag = "12")]
+    pub has_data: bool,
 }
 /// Server-owned behavior for one logical column returned in table details.
 #[derive(Clone, PartialEq, Eq, Hash, ::prost::Message)]
diff --git a/server b/server
index f559f57d..fe581213 160000
--- a/server
+++ b/server
@@ -1 +1 @@
-Subproject commit f559f57d40b9b0b8821ff9a924b2392903302813
+Subproject commit fe58121374af694f5d1cea0a6d1e82bad8511660
diff --git a/web/CHANGELOG.md b/web/CHANGELOG.md
index f65757e6..b47a30c2 100644
--- a/web/CHANGELOG.md
+++ b/web/CHANGELOG.md
@@ -16,10 +16,15 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ### Changed
 
+- **Backend-provided rate-source suggestions** — the add-table page calls
+  `ExchangeRateService.ListRateSources` and offers the returned provider IDs
+  through the rate-source autocomplete field; initial foreign currencies use
+  the same ISO-4217 autocomplete options as the accounting currency.
 - **Editable empty-table definitions** — the table-definition column page now
   calls `PutTableDefinition` to atomically remove selected columns and append
   replacements, with stable column identities and optimistic revision checks.
-  Add-only changes continue to work for populated tables.
+  It is clearly labelled “Adjust table” only while the table is empty; after
+  data is posted, the page switches to append-only “Add columns” mode.
 - **The shared profile is named by the backend** — `ProfileTreeResponse`
   gained `shared_profile_name`, and every page that browses the shared tables
   now reads the name from there instead of spelling `__global` itself. Catalog
diff --git a/web/locales/cs/main.ftl b/web/locales/cs/main.ftl
index 2320c00f..d29b367d 100644
--- a/web/locales/cs/main.ftl
+++ b/web/locales/cs/main.ftl
@@ -161,12 +161,12 @@ admin-system-columns-label = Systémové sloupce · skryté před uživateli
 
 # --- Stránky definice tabulky (přidat sloupce / zobrazení / smazat / kopírovat / šablona / historie)
 td-add-columns-title = Přidat sloupce
-td-adjust-columns-title = Upravit sloupce
+td-adjust-table-title = Upravit tabulku
 td-presentation-title = Zobrazení sloupců
 td-add-columns-to = Přidat sloupce do
 td-append-hint = Sloupce se přidávají na konec. Nic, co už existuje, se nemění a nové sloupce lze indexovat hned při přidání.
-td-adjust-columns-of = Upravit sloupce tabulky
-td-adjust-hint = Přidejte nové sloupce nebo označte existující k odebrání. Samotné přidání funguje i v tabulce s daty; odebrání nebo nahrazení vyžaduje prázdnou tabulku a uloží se atomicky.
+td-adjust-table-of = Upravit tabulku
+td-adjust-table-hint = Tato tabulka neobsahuje data, takže můžete přidat nové sloupce nebo označit existující k odebrání. Změna se uloží atomicky.
 td-existing-columns = Existující sloupce
 td-new-columns = Nové sloupce k přidání
 td-remove-column = Odebrat
@@ -258,8 +258,8 @@ td-global-label = Globální — všechny profily
 td-tab-aria = akce s tabulkou
 td-tab-add-columns = Přidat sloupce
 td-tab-add-columns-sub = Připojit nové sloupce
-td-tab-adjust-columns = Upravit sloupce
-td-tab-adjust-columns-sub = Přidat, odebrat nebo nahradit
+td-tab-adjust-table = Upravit tabulku
+td-tab-adjust-table-sub = Přidat, odebrat nebo nahradit sloupce
 td-tab-presentation = Zobrazení
 td-tab-presentation-sub = Změnit aliasy a pořadí
 td-tab-delete = Smazat
@@ -338,6 +338,7 @@ td-err-describe-column = Před přidáním popište alespoň jeden sloupec.
 td-err-describe-change = Označte sloupec k odebrání nebo připravte alespoň jeden sloupec k přidání.
 td-err-backend-no-columns = Backend nepřidal sloupce.
 td-err-backend-no-adjustment = Backend neupravil definici tabulky.
+td-err-populated-append-only = Tato tabulka obsahuje data. Existující sloupce nelze odebrat; lze pouze přidat nové sloupce.
 td-err-choose-rename = Zadejte nový název sloupce.
 td-err-unknown-column = Tento sloupec už do této tabulky nepatří. Panel níže ukazuje tabulku, jaká je teď.
 td-err-backend-no-rename = Backend nepřejmenoval sloupec.
diff --git a/web/locales/en/main.ftl b/web/locales/en/main.ftl
index 249ddc62..134515b3 100644
--- a/web/locales/en/main.ftl
+++ b/web/locales/en/main.ftl
@@ -163,12 +163,12 @@ admin-system-columns-label = System columns · hidden from users
 
 # --- Table definition pages (add columns / presentation / delete / copy / template / history) -
 td-add-columns-title = Add columns
-td-adjust-columns-title = Adjust columns
+td-adjust-table-title = Adjust table
 td-presentation-title = Column presentation
 td-add-columns-to = Add columns to
 td-append-hint = Columns are appended. Nothing that already exists is changed, and the new columns can be indexed as they are added.
-td-adjust-columns-of = Adjust columns of
-td-adjust-hint = Add new columns, or select existing columns to remove. Add-only changes also work on populated tables; removing or replacing columns requires an empty table and is saved atomically.
+td-adjust-table-of = Adjust table
+td-adjust-table-hint = This table has no data, so you can add new columns or select existing columns to remove. The change is saved atomically.
 td-existing-columns = Existing columns
 td-new-columns = New columns to add
 td-remove-column = Remove
@@ -258,8 +258,8 @@ td-global-label = Global — all profiles
 td-tab-aria = table actions
 td-tab-add-columns = Add columns
 td-tab-add-columns-sub = Append new columns
-td-tab-adjust-columns = Adjust columns
-td-tab-adjust-columns-sub = Add, remove, or replace columns
+td-tab-adjust-table = Adjust table
+td-tab-adjust-table-sub = Add, remove, or replace columns
 td-tab-presentation = Presentation
 td-tab-presentation-sub = Change aliases and order
 td-tab-delete = Delete
@@ -334,6 +334,7 @@ td-err-describe-column = Describe at least one column before adding.
 td-err-describe-change = Select a column to remove or stage at least one column to add.
 td-err-backend-no-columns = The backend did not add the columns.
 td-err-backend-no-adjustment = The backend did not adjust the table definition.
+td-err-populated-append-only = This table contains data. Existing columns cannot be removed; only new columns can be added.
 td-err-choose-rename = Type a new name for the column.
 td-err-unknown-column = That column is not part of this table any more. The panel below is the table as it now is.
 td-err-backend-no-rename = The backend did not rename the column.
diff --git a/web/locales/sk/main.ftl b/web/locales/sk/main.ftl
index dbb48c89..7f7a4859 100644
--- a/web/locales/sk/main.ftl
+++ b/web/locales/sk/main.ftl
@@ -161,12 +161,12 @@ admin-system-columns-label = Systémové stĺpce · skryté pred používateľmi
 
 # --- Stránky definície tabuľky (pridať stĺpce / zobrazenie / vymazať / kopírovať / šablóna / história)
 td-add-columns-title = Pridať stĺpce
-td-adjust-columns-title = Upraviť stĺpce
+td-adjust-table-title = Upraviť tabuľku
 td-presentation-title = Zobrazenie stĺpcov
 td-add-columns-to = Pridať stĺpce do
 td-append-hint = Stĺpce sa pridávajú na koniec. Nič, čo už existuje, sa nemení a nové stĺpce možno indexovať hneď pri pridaní.
-td-adjust-columns-of = Upraviť stĺpce tabuľky
-td-adjust-hint = Pridajte nové stĺpce alebo označte existujúce na odstránenie. Samotné pridanie funguje aj v tabuľke s údajmi; odstránenie alebo nahradenie vyžaduje prázdnu tabuľku a uloží sa atómovo.
+td-adjust-table-of = Upraviť tabuľku
+td-adjust-table-hint = Táto tabuľka neobsahuje údaje, takže môžete pridať nové stĺpce alebo označiť existujúce na odstránenie. Zmena sa uloží atómovo.
 td-existing-columns = Existujúce stĺpce
 td-new-columns = Nové stĺpce na pridanie
 td-remove-column = Odstrániť
@@ -258,8 +258,8 @@ td-global-label = Globálne — všetky profily
 td-tab-aria = akcie s tabuľkou
 td-tab-add-columns = Pridať stĺpce
 td-tab-add-columns-sub = Pripojiť nové stĺpce
-td-tab-adjust-columns = Upraviť stĺpce
-td-tab-adjust-columns-sub = Pridať, odstrániť alebo nahradiť
+td-tab-adjust-table = Upraviť tabuľku
+td-tab-adjust-table-sub = Pridať, odstrániť alebo nahradiť stĺpce
 td-tab-presentation = Zobrazenie
 td-tab-presentation-sub = Zmeniť aliasy a poradie
 td-tab-delete = Vymazať
@@ -338,6 +338,7 @@ td-err-describe-column = Pred pridaním popíšte aspoň jeden stĺpec.
 td-err-describe-change = Označte stĺpec na odstránenie alebo pripravte aspoň jeden stĺpec na pridanie.
 td-err-backend-no-columns = Backend nepridal stĺpce.
 td-err-backend-no-adjustment = Backend neupravil definíciu tabuľky.
+td-err-populated-append-only = Táto tabuľka obsahuje údaje. Existujúce stĺpce nemožno odstrániť; možno iba pridať nové stĺpce.
 td-err-choose-rename = Zadajte nový názov stĺpca.
 td-err-unknown-column = Tento stĺpec už do tejto tabuľky nepatrí. Panel nižšie ukazuje tabuľku, aká je teraz.
 td-err-backend-no-rename = Backend nepremenoval stĺpec.
diff --git a/web/src/lib.rs b/web/src/lib.rs
index f51dbe74..62baea50 100644
--- a/web/src/lib.rs
+++ b/web/src/lib.rs
@@ -88,7 +88,8 @@ mod definitions {
 
 use auth::auth_service_client::AuthServiceClient;
 use definitions::{
-    ecb, table_definition::table_definition_client::TableDefinitionClient,
+    ecb, exchange_rates::exchange_rate_service_client::ExchangeRateServiceClient,
+    table_definition::table_definition_client::TableDefinitionClient,
     table_script::table_script_client::TableScriptClient,
     table_structure::table_structure_service_client::TableStructureServiceClient,
     table_validation::table_validation_service_client::TableValidationServiceClient,
@@ -113,6 +114,7 @@ pub(crate) struct AppState {
     validations: TableValidationServiceClient<Channel>,
     tables_data: TablesDataClient<Channel>,
     ecb: EcbServiceClient<Channel>,
+    exchange_rates: ExchangeRateServiceClient<Channel>,
     /// The imports this process is running, which the import page polls. Not a
     /// client: an import outlives the request that started it, so where it has
     /// got to has to live somewhere both the task and the next request can see.
@@ -149,6 +151,7 @@ pub async fn serve() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
         validations: TableValidationServiceClient::new(channel.clone()),
         tables_data: TablesDataClient::new(channel.clone()),
         ecb: EcbServiceClient::new(channel.clone()),
+        exchange_rates: ExchangeRateServiceClient::new(channel.clone()),
         structures: TableStructureServiceClient::new(channel),
         imports: Default::default(),
     };
@@ -215,6 +218,7 @@ mod tests {
             validations: TableValidationServiceClient::new(channel.clone()),
             tables_data: TablesDataClient::new(channel.clone()),
             ecb: EcbServiceClient::new(channel.clone()),
+            exchange_rates: ExchangeRateServiceClient::new(channel.clone()),
             structures: TableStructureServiceClient::new(channel),
             imports: Default::default(),
         })
diff --git a/web/src/pages/add_table/loader.rs b/web/src/pages/add_table/loader.rs
index 0b76930f..a5f38f25 100644
--- a/web/src/pages/add_table/loader.rs
+++ b/web/src/pages/add_table/loader.rs
@@ -40,6 +40,19 @@ pub(crate) async fn load_page(
         return Err(LoadError::Forbidden);
     }
 
+    let mut exchange_rates = state.exchange_rates.clone();
+    let rate_sources = exchange_rates
+        .list_rate_sources(
+            authenticated_request(headers, Empty {}).map_err(|_| LoadError::Unauthenticated)?,
+        )
+        .await
+        .map_err(|error| LoadError::Backend(error.message().to_string()))?
+        .into_inner()
+        .sources
+        .into_iter()
+        .map(|source| source.id)
+        .collect();
+
     let mut definitions = state.definitions;
     // What a column may be is the backend's to say; the picker and every rule
     // the draft applies are read from this.
@@ -135,6 +148,7 @@ pub(crate) async fn load_page(
             .into_iter()
             .map(|profile| profile.name)
             .collect(),
+        rate_sources,
         draft,
         status,
         error,
diff --git a/web/src/pages/add_table/logic.rs b/web/src/pages/add_table/logic.rs
index 2564bf0d..17292719 100644
--- a/web/src/pages/add_table/logic.rs
+++ b/web/src/pages/add_table/logic.rs
@@ -249,6 +249,7 @@ mod tests {
             nav: crate::ui::Nav::default(),
             shared_profile: "__global".to_string(),
             profiles: vec!["billing".to_string()],
+            rate_sources: vec!["ecb".to_string()],
             draft,
             status: None,
             error: None,
diff --git a/web/src/pages/add_table/state.rs b/web/src/pages/add_table/state.rs
index 8870f363..1a286f5e 100644
--- a/web/src/pages/add_table/state.rs
+++ b/web/src/pages/add_table/state.rs
@@ -198,6 +198,8 @@ impl BuilderForm {
 pub(crate) struct AddTablePageState {
     pub nav: crate::ui::Nav,
     pub profiles: Vec<String>,
+    /// Provider IDs returned by ExchangeRateService.ListRateSources.
+    pub rate_sources: Vec<String>,
     /// The profile a global table lands in, as the profile tree reports it.
     /// The builder posts it as the created table's scope.
     pub shared_profile: String,
@@ -511,6 +513,7 @@ mod tests {
             nav: crate::ui::Nav::default(),
             shared_profile: "__global".to_string(),
             profiles: Vec::new(),
+            rate_sources: vec!["ecb".to_string()],
             draft: posted_form().to_draft(),
             status: None,
             error: None,
@@ -597,6 +600,7 @@ mod tests {
             nav: crate::ui::Nav::default(),
             shared_profile: "__global".to_string(),
             profiles: Vec::new(),
+            rate_sources: vec!["ecb".to_string()],
             draft,
             status: None,
             error: None,
diff --git a/web/src/pages/add_table/ui.rs b/web/src/pages/add_table/ui.rs
index a64475f5..bb8dea0f 100644
--- a/web/src/pages/add_table/ui.rs
+++ b/web/src/pages/add_table/ui.rs
@@ -111,6 +111,7 @@ mod tests {
             nav: Nav::default(),
             shared_profile: "__global".to_string(),
             profiles: vec!["billing".to_string()],
+            rate_sources: vec!["ecb".to_string()],
             draft,
             status: None,
             error: None,
@@ -221,13 +222,15 @@ mod tests {
     }
 
     #[test]
-    fn the_page_offers_the_new_profile_option_and_the_currency_list() {
+    fn the_page_offers_backend_vocabularies_for_profile_setup() {
         let html = render_page(&page());
 
         assert!(!html.contains("Template error"), "{html}");
         assert!(html.contains(r#"value="__new__""#));
         assert!(html.contains(r#"<datalist id="currency-codes">"#));
         assert!(html.contains(r#"<option value="EUR">"#));
+        assert!(html.contains(r#"<datalist id="rate-source-ids">"#));
+        assert!(html.contains(r#"<option value="ecb">"#));
     }
 
     #[test]
@@ -373,7 +376,16 @@ mod tests {
         state.draft.creating_new_profile = true;
         let html = render_builder(&state);
         assert!(html.contains(r#"name="profile_name_input""#));
-        assert!(html.contains(r#"name="accounting_currency" value="EUR" list="currency-codes""#));
+        assert!(html.contains(r#"name="accounting_currency""#));
+        assert!(html.contains(r#"list="currency-codes""#));
+        assert!(html.contains(r#"name="rate_source_id""#));
+        assert!(html.contains(r#"list="rate-source-ids""#));
+        let foreign_currency_input = html
+            .split(r#"name="foreign_currencies""#)
+            .nth(1)
+            .and_then(|rest| rest.split('>').next())
+            .expect("the initial foreign-currency input should be rendered");
+        assert!(foreign_currency_input.contains(r#"list="currency-codes""#));
     }
 
     /// The dialog only exists when there is a failure, and it carries the same
diff --git a/web/src/pages/admin/table_definition/loader.rs b/web/src/pages/admin/table_definition/loader.rs
index 39951d6b..d501d205 100644
--- a/web/src/pages/admin/table_definition/loader.rs
+++ b/web/src/pages/admin/table_definition/loader.rs
@@ -202,6 +202,7 @@ pub(crate) async fn load_page(
                 .map(|table| TableDetailView {
                     id: table.id,
                     row_version: table.row_version,
+                    has_data: table.has_data,
                     columns: table
                         .columns
                         .iter()
diff --git a/web/src/pages/admin/table_definition/logic.rs b/web/src/pages/admin/table_definition/logic.rs
index 0ef6f6d4..014b80f2 100644
--- a/web/src/pages/admin/table_definition/logic.rs
+++ b/web/src/pages/admin/table_definition/logic.rs
@@ -215,8 +215,8 @@ pub(crate) async fn update_columns(
     }
 }
 
-/// POST /admin/tables/columns/add — append columns, or atomically replace part
-/// of an empty table through PutTableDefinition.
+/// POST /admin/tables/columns/add — atomically adjust an empty table, or append
+/// columns once the table contains data.
 pub(crate) async fn add_columns(
     State(state): State<AppState>,
     headers: HeaderMap,
@@ -275,13 +275,6 @@ pub(crate) async fn add_columns(
         return refuse(state, headers, inputs, Page::AddColumns, message).await;
     }
 
-    // Keep the old append capability for populated tables. Put is used only
-    // when a removal was requested, because that operation deliberately
-    // refuses every table which has ever stored a row.
-    if inputs.remove_column_ids.is_empty() {
-        return append_columns(state, headers, inputs, catalog, definitions).await;
-    }
-
     let current = match load_page(state.clone(), &headers, inputs.clone()).await {
         Ok(page) => page.detail,
         Err(error) => return load_error_response(&headers, error),
@@ -290,6 +283,19 @@ pub(crate) async fn add_columns(
         let message = tr!(Locale::from_headers(&headers), "td-err-select-table-first");
         return refuse(state, headers, inputs, Page::AddColumns, message).await;
     };
+
+    // The read model makes the mode explicit: an empty table is adjusted with
+    // PutTableDefinition, while a populated table exposes append-only changes.
+    // Re-checking here also keeps crafted posts from smuggling removals through
+    // the append-only UI.
+    if current.has_data {
+        if !inputs.remove_column_ids.is_empty() {
+            let message = tr!(Locale::from_headers(&headers), "td-err-populated-append-only");
+            return refuse(state, headers, inputs, Page::AddColumns, message).await;
+        }
+        return append_columns(state, headers, inputs, catalog, definitions).await;
+    }
+
     let remove_column_ids = match current.expanded_removal_ids(&inputs.remove_column_ids) {
         Ok(ids) => ids,
         Err(()) => {
diff --git a/web/src/pages/admin/table_definition/state.rs b/web/src/pages/admin/table_definition/state.rs
index a9c38e5f..3266c37a 100644
--- a/web/src/pages/admin/table_definition/state.rs
+++ b/web/src/pages/admin/table_definition/state.rs
@@ -85,6 +85,7 @@ impl TableSummary {
 pub(crate) struct TableDetailView {
     pub id: i64,
     pub row_version: i64,
+    pub has_data: bool,
     pub row_display_columns: Vec<String>,
     pub columns: Vec<DetailColumn>,
     pub scripts: Vec<ScriptView>,
@@ -377,6 +378,12 @@ pub(crate) struct TableDefinitionPageState {
 }
 
 impl TableDefinitionPageState {
+    /// Empty dynamic tables may be reshaped atomically. Once data exists, the
+    /// backend deliberately exposes only append-only column changes.
+    pub(crate) fn can_adjust_definition(&self) -> bool {
+        self.table_is_writable() && self.detail.as_ref().is_some_and(|detail| !detail.has_data)
+    }
+
     pub(crate) fn column_is_selected_for_removal(&self, column_id: &i64) -> bool {
         self.remove_column_ids.contains(column_id)
     }
@@ -486,6 +493,7 @@ mod tests {
         let detail = TableDetailView {
             id: 1,
             row_version: 1,
+            has_data: false,
             row_display_columns: Vec::new(),
             scripts: Vec::new(),
             columns: vec![
diff --git a/web/src/pages/admin/table_definition/ui.rs b/web/src/pages/admin/table_definition/ui.rs
index dd219153..42e2f364 100644
--- a/web/src/pages/admin/table_definition/ui.rs
+++ b/web/src/pages/admin/table_definition/ui.rs
@@ -273,6 +273,7 @@ mod tests {
             detail: Some(TableDetailView {
                 id: 7,
                 row_version: 1,
+                has_data: false,
                 row_display_columns: vec!["number".to_string()],
                 scripts: Vec::new(),
                 columns: vec![DetailColumn {
@@ -456,7 +457,7 @@ mod tests {
         assert!(add_html.contains(r#"id="column-form""#), "{add_html}");
         assert!(add_html.contains(r#"name="expected_row_version" value="1""#), "{add_html}");
         assert!(add_html.contains(r#"name="remove_column_ids" value="1""#), "{add_html}");
-        assert!(add_html.contains("Adjust columns"), "{add_html}");
+        assert!(add_html.contains("Adjust table"), "{add_html}");
         assert!(!add_html.contains(r#"name="alias""#), "{add_html}");
 
         let presentation_html = render_presentation_page(&page());
@@ -464,6 +465,19 @@ mod tests {
         assert!(!presentation_html.contains(r#"id="column-form""#), "{presentation_html}");
     }
 
+    #[test]
+    fn a_populated_table_offers_append_only_columns() {
+        let mut state = page();
+        state.detail.as_mut().unwrap().has_data = true;
+
+        let html = render_add_columns_page(&state);
+
+        assert!(html.contains("Add columns"), "{html}");
+        assert!(html.contains("Columns are appended"), "{html}");
+        assert!(!html.contains(r#"name="remove_column_ids""#), "{html}");
+        assert!(!html.contains("Save table definition"), "{html}");
+    }
+
     /// The profile-wide pages need only a profile, and say so by still
     /// rendering with no table selected.
     #[test]
diff --git a/web/templates/pages/add_table/add_table.html b/web/templates/pages/add_table/add_table.html
index a4faab88..91da3996 100644
--- a/web/templates/pages/add_table/add_table.html
+++ b/web/templates/pages/add_table/add_table.html
@@ -21,4 +21,7 @@
 <datalist id="currency-codes">
   {% for code in currency_codes %}<option value="{{ code }}"></option>{% endfor %}
 </datalist>
+<datalist id="rate-source-ids">
+  {% for source in page.rate_sources %}<option value="{{ source }}"></option>{% endfor %}
+</datalist>
 {% endblock %}
diff --git a/web/templates/pages/add_table/builder.html b/web/templates/pages/add_table/builder.html
index b539ea83..a7028e96 100644
--- a/web/templates/pages/add_table/builder.html
+++ b/web/templates/pages/add_table/builder.html
@@ -85,11 +85,11 @@
       </label>
       <label>Rate source
         <input name="rate_source_id" value="{{ page.draft.rate_source_id }}"
-               placeholder="provider-id">
+               list="rate-source-ids" placeholder="provider-id">
       </label>
       <label>Initial foreign currencies
         <input name="foreign_currencies" value="{{ page.draft.foreign_currencies }}"
-               placeholder="CZK, USD">
+               list="currency-codes" placeholder="CZK, USD">
       </label>
     {% else %}
       <input type="hidden" name="accounting_currency" value="{{ page.draft.accounting_currency }}">
diff --git a/web/templates/pages/admin/table_definition/add_columns.html b/web/templates/pages/admin/table_definition/add_columns.html
index 77041954..a39b1e8d 100644
--- a/web/templates/pages/admin/table_definition/add_columns.html
+++ b/web/templates/pages/admin/table_definition/add_columns.html
@@ -1,7 +1,7 @@
 {# GET /admin/tables/columns/add — crate::pages::admin::table_definition::ui::AddColumnsPage #}
 {% extends "ui/base.html" %}
 
-{% block title %}{{ nav.tr("td-adjust-columns-title") }}{% endblock %}
+{% block title %}{% if page.can_adjust_definition() %}{{ nav.tr("td-adjust-table-title") }}{% else %}{{ nav.tr("td-add-columns-title") }}{% endif %}{% endblock %}
 
 {% block content %}
 <main>
diff --git a/web/templates/pages/admin/table_definition/add_columns_panel.html b/web/templates/pages/admin/table_definition/add_columns_panel.html
index 11004114..3c7134f2 100644
--- a/web/templates/pages/admin/table_definition/add_columns_panel.html
+++ b/web/templates/pages/admin/table_definition/add_columns_panel.html
@@ -3,13 +3,18 @@
 
 {% if page.table_is_writable() %}
   <section class="panel">
-    <h2>{{ nav.tr("td-adjust-columns-of") }} <code>{{ page.selection.table }}</code></h2>
-    <p class="hint">{{ nav.tr("td-adjust-hint") }}</p>
+    {% if page.can_adjust_definition() %}
+      <h2>{{ nav.tr("td-adjust-table-of") }} <code>{{ page.selection.table }}</code></h2>
+      <p class="hint">{{ nav.tr("td-adjust-table-hint") }}</p>
+    {% else %}
+      <h2>{{ nav.tr("td-add-columns-to") }} <code>{{ page.selection.table }}</code></h2>
+      <p class="hint">{{ nav.tr("td-append-hint") }}</p>
+    {% endif %}
     <form id="column-form"
           hx-post="/admin/tables/columns/add{{ page.selection.query() }}"
           hx-target="#table-panel" hx-swap="innerHTML"
           hx-disabled-elt="button[type=submit]">
-      {% if let Some(detail) = page.detail %}
+      {% if page.can_adjust_definition() %}{% if let Some(detail) = page.detail %}
         <input type="hidden" name="expected_row_version" value="{{ detail.row_version }}">
         <h3>{{ nav.tr("td-existing-columns") }}</h3>
         <table class="builder-table">
@@ -34,7 +39,7 @@
             {% endfor %}
           </tbody>
         </table>
-      {% endif %}
+      {% endif %}{% endif %}
       <h3>{{ nav.tr("td-new-columns") }}</h3>
       <div id="column-panel">
         {% include "pages/admin/table_definition/column_panel.html" %}
diff --git a/web/templates/pages/admin/table_definition/column_panel.html b/web/templates/pages/admin/table_definition/column_panel.html
index b7256a0c..05812957 100644
--- a/web/templates/pages/admin/table_definition/column_panel.html
+++ b/web/templates/pages/admin/table_definition/column_panel.html
@@ -216,5 +216,5 @@
 {% endfor %}
 
 <div class="form-actions">
-  <button type="submit">{{ nav.tr("td-save-definition") }}</button>
+  <button type="submit">{% if page.can_adjust_definition() %}{{ nav.tr("td-save-definition") }}{% else %}{{ nav.tr("td-add-columns-title") }}{% endif %}</button>
 </div>
diff --git a/web/templates/pages/admin/table_definition/context.html b/web/templates/pages/admin/table_definition/context.html
index a3a4b524..3794db87 100644
--- a/web/templates/pages/admin/table_definition/context.html
+++ b/web/templates/pages/admin/table_definition/context.html
@@ -40,7 +40,11 @@
   {% if page.selection.has_table() %}
     {% if page.table_is_writable() %}
       <a href="/admin/tables/columns/add{{ page.selection.query() }}" class="tab {% if page.is("add-columns") %}selected{% endif %}" {% if page.is("add-columns") %}aria-current="page"{% endif %}>
-        <span>{{ nav.tr("td-tab-adjust-columns") }}</span><small>{{ nav.tr("td-tab-adjust-columns-sub") }}</small>
+        {% if page.can_adjust_definition() %}
+          <span>{{ nav.tr("td-tab-adjust-table") }}</span><small>{{ nav.tr("td-tab-adjust-table-sub") }}</small>
+        {% else %}
+          <span>{{ nav.tr("td-tab-add-columns") }}</span><small>{{ nav.tr("td-tab-add-columns-sub") }}</small>
+        {% endif %}
       </a>
       <a href="/admin/tables/presentation{{ page.selection.query() }}" class="tab {% if page.is("presentation") %}selected{% endif %}" {% if page.is("presentation") %}aria-current="page"{% endif %}>
         <span>{{ nav.tr("td-tab-presentation") }}</span><small>{{ nav.tr("td-tab-presentation-sub") }}</small>