diff --git a/Cargo.lock b/Cargo.lock
index f48dc70b..e5460370 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -207,7 +207,7 @@ dependencies = [
  "objc2-foundation",
  "parking_lot",
  "percent-encoding",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
  "x11rb",
 ]
 
@@ -1161,7 +1161,7 @@ checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
 
 [[package]]
 name = "client"
-version = "0.8.46"
+version = "0.8.48"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -1282,7 +1282,7 @@ dependencies = [
 
 [[package]]
 name = "common"
-version = "0.8.46"
+version = "0.8.48"
 dependencies = [
  "prost",
  "prost-build",
@@ -2571,7 +2571,7 @@ dependencies = [
  "libc",
  "option-ext",
  "redox_users",
- "windows-sys 0.61.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -2735,7 +2735,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -4730,7 +4730,7 @@ version = "0.50.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7957b9740744892f114936ab4a57b3f487491bbeafaf8083688b16841a4240e5"
 dependencies = [
- "windows-sys 0.61.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -5906,7 +5906,7 @@ dependencies = [
  "once_cell",
  "socket2",
  "tracing",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -6590,7 +6590,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -6647,7 +6647,7 @@ dependencies = [
  "security-framework",
  "security-framework-sys",
  "webpki-root-certs",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -6754,7 +6754,7 @@ checksum = "1c107b6f4780854c8b126e228ea8869f4d7b71260f962fefb57b996b8959ba6b"
 
 [[package]]
 name = "search"
-version = "0.8.46"
+version = "0.8.48"
 dependencies = [
  "anyhow",
  "common",
@@ -6942,7 +6942,7 @@ dependencies = [
 
 [[package]]
 name = "server"
-version = "0.8.46"
+version = "0.8.48"
 dependencies = [
  "anyhow",
  "bcrypt",
@@ -7931,7 +7931,7 @@ dependencies = [
  "getrandom 0.4.2",
  "once_cell",
  "rustix",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -8534,7 +8534,7 @@ checksum = "e78122066b0cb818b8afd08f7ed22f7fdbc3e90815035726f0840d0d26c0747a"
 
 [[package]]
 name = "tui-canvas"
-version = "0.8.46"
+version = "0.8.48"
 dependencies = [
  "anyhow",
  "arboard",
@@ -8565,7 +8565,7 @@ dependencies = [
 
 [[package]]
 name = "tui-canvas-validation-core"
-version = "0.8.46"
+version = "0.8.48"
 dependencies = [
  "regex",
  "serde",
@@ -8575,7 +8575,7 @@ dependencies = [
 
 [[package]]
 name = "tui-pages"
-version = "0.8.46"
+version = "0.8.48"
 dependencies = [
  "criterion",
  "crossterm",
@@ -9286,7 +9286,7 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
diff --git a/README.md b/README.md
index 6e1f5d06..5522e43c 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,10 @@
 TUI accounting system. Client/server application with two extracted open-source
 libraries.
 
+Column designers default to unconstrained exact decimals. The legacy-compatible
+fixed-scale form is an explicit advanced option; see
+[`docs/fixed-scale-decimal.md`](docs/fixed-scale-decimal.md).
+
 ## Crates
 
 | Crate | What | Published |
diff --git a/client b/client
index fc712732..1e0b6f9e 160000
--- a/client
+++ b/client
@@ -1 +1 @@
-Subproject commit fc712732df6521160302fd6ace06261fd8336f53
+Subproject commit 1e0b6f9edea67aaafc99acdbec0cd55dcadb8f05
diff --git a/docs/fixed-scale-decimal.md b/docs/fixed-scale-decimal.md
new file mode 100644
index 00000000..ecf03c87
--- /dev/null
+++ b/docs/fixed-scale-decimal.md
@@ -0,0 +1,26 @@
+# Decimal column policy
+
+Use the bare `numeric` column type for ordinary exact base-10 values. It stores
+the value without a schema-defined decimal-place limit and is the recommended
+choice for quantities, percentages, rates, ratios and measurements. Use
+`money` for currency amounts; its currency and rounding policy are separate
+from this document.
+
+`decimal(p,s)` is an advanced, opt-in compatibility type for strict external
+data contracts. `p` limits the total digits and `s` limits the fractional
+digits. It is hidden from the normal table-designer type list until fixed-scale
+decimal is enabled for that editing session.
+
+Fixed scale is intentionally strict:
+
+- API input outside the declared precision or scale is rejected, never
+  silently rounded by PostgreSQL.
+- A table script targeting a fixed-scale column must round explicitly before
+  returning its value.
+- A fixed-scale type cannot be changed through the table editor after the
+  table contains data.
+- Display precision, allowed increments, minimums and maximums are business
+  validation concerns; `decimal(p,s)` is not a substitute for them.
+
+Existing fixed-scale columns remain supported. The opt-in changes discovery,
+not storage compatibility.
diff --git a/server b/server
index 0fd5a16b..cf752c7e 160000
--- a/server
+++ b/server
@@ -1 +1 @@
-Subproject commit 0fd5a16ba6ac0671daabfa5fcbf34bd24c12d80c
+Subproject commit cf752c7ee96c3019573e7c2f5f54571e5c4f93fc
diff --git a/web/locales/cs/main.ftl b/web/locales/cs/main.ftl
index fefcdf67..3c037f1d 100644
--- a/web/locales/cs/main.ftl
+++ b/web/locales/cs/main.ftl
@@ -212,6 +212,15 @@ td-precision = Přesnost
 td-precision-hint = Celkový počet uložených číslic, alespoň 1.
 td-scale = Desetinná místa
 td-scale-hint = Číslice za desetinnou čárkou, nejvýše tolik jako přesnost.
+td-fixed-decimal-access = Pokročilé číselné typy
+td-fixed-decimal-disabled = Pouze doporučené typy
+td-fixed-decimal-enabled = Povolit desetinné číslo s pevným měřítkem
+td-fixed-decimal-access-hint = Doporučuje se přesný typ NUMERIC. Tuto možnost povolte pouze pro přísný externí datový kontrakt.
+td-fixed-decimal-warning-title = Pokročilé desetinné číslo s pevným měřítkem
+td-fixed-decimal-warning = Tento typ omezuje celkový počet číslic i desetinná místa. Hodnoty mimo měřítko se odmítnou, výpočty musí zaokrouhlovat explicitně a typ po vložení dat nelze změnit.
+td-fixed-decimal-enable-first = Před použitím tohoto typu povolte pokročilé desetinné číslo s pevným měřítkem.
+td-exact-decimal = Desetinné číslo — přesné (doporučeno)
+td-fixed-decimal-type = Desetinné číslo s pevným měřítkem — pokročilé
 td-referenced-table = Odkazovaná tabulka
 td-choose-table = Vyberte tabulku
 td-group-global = Globální
diff --git a/web/locales/en/main.ftl b/web/locales/en/main.ftl
index e31c0270..4781bb54 100644
--- a/web/locales/en/main.ftl
+++ b/web/locales/en/main.ftl
@@ -216,6 +216,15 @@ td-precision = Precision
 td-precision-hint = Total digits stored, at least 1.
 td-scale = Scale
 td-scale-hint = Digits after the point, no more than the precision.
+td-fixed-decimal-access = Advanced number types
+td-fixed-decimal-disabled = Recommended types only
+td-fixed-decimal-enabled = Enable fixed-scale decimal
+td-fixed-decimal-access-hint = Exact NUMERIC is recommended. Enable this only for a strict external data contract.
+td-fixed-decimal-warning-title = Advanced fixed-scale decimal
+td-fixed-decimal-warning = This type limits total and fractional digits. Values outside the declared scale are refused, calculations must round explicitly, and the type cannot be changed after the table contains data.
+td-fixed-decimal-enable-first = Enable advanced fixed-scale decimal before using this type.
+td-exact-decimal = Decimal — exact (recommended)
+td-fixed-decimal-type = Fixed-scale decimal — advanced
 td-referenced-table = Referenced table
 td-choose-table = Choose a table
 td-group-global = Global
diff --git a/web/locales/sk/main.ftl b/web/locales/sk/main.ftl
index eede2884..fed69c74 100644
--- a/web/locales/sk/main.ftl
+++ b/web/locales/sk/main.ftl
@@ -212,6 +212,15 @@ td-precision = Presnosť
 td-precision-hint = Celkový počet uložených číslic, aspoň 1.
 td-scale = Desatinné miesta
 td-scale-hint = Číslice za desatinnou čiarkou, najviac toľko ako presnosť.
+td-fixed-decimal-access = Pokročilé číselné typy
+td-fixed-decimal-disabled = Iba odporúčané typy
+td-fixed-decimal-enabled = Povoliť desatinné číslo s pevnou mierkou
+td-fixed-decimal-access-hint = Odporúča sa presný typ NUMERIC. Túto možnosť povoľte iba pre prísnu externú dátovú zmluvu.
+td-fixed-decimal-warning-title = Pokročilé desatinné číslo s pevnou mierkou
+td-fixed-decimal-warning = Tento typ obmedzuje celkový počet číslic aj desatinné miesta. Hodnoty mimo mierky sa odmietnu, výpočty musia zaokrúhľovať explicitne a typ sa po vložení údajov nedá zmeniť.
+td-fixed-decimal-enable-first = Pred použitím tohto typu povoľte pokročilé desatinné číslo s pevnou mierkou.
+td-exact-decimal = Desatinné číslo — presné (odporúčané)
+td-fixed-decimal-type = Desatinné číslo s pevnou mierkou — pokročilé
 td-referenced-table = Odkazovaná tabuľka
 td-choose-table = Vyberte tabuľku
 td-group-global = Globálne
diff --git a/web/src/pages/add_table/state.rs b/web/src/pages/add_table/state.rs
index 1a286f5e..69dbde55 100644
--- a/web/src/pages/add_table/state.rs
+++ b/web/src/pages/add_table/state.rs
@@ -61,6 +61,8 @@ pub(crate) struct BuilderForm {
     #[serde(default)]
     pub decimal_scale_input: String,
     #[serde(default)]
+    pub fixed_decimal_input: String,
+    #[serde(default)]
     pub column_indexing_input: String,
     #[serde(default)]
     pub column_quantity_ledger_input: String,
@@ -128,6 +130,7 @@ impl BuilderForm {
             link_table_input: self.link_table_input.clone(),
             decimal_precision_input: self.decimal_precision_input.clone(),
             decimal_scale_input: self.decimal_scale_input.clone(),
+            fixed_decimal_input: self.fixed_decimal_input.clone(),
             indexing_input: self.column_indexing_input.clone(),
             quantity_ledger_input: self.column_quantity_ledger_input.clone(),
             required_input: self.column_required_input.clone(),
diff --git a/web/src/pages/add_table/ui.rs b/web/src/pages/add_table/ui.rs
index bb8dea0f..459766fb 100644
--- a/web/src/pages/add_table/ui.rs
+++ b/web/src/pages/add_table/ui.rs
@@ -245,11 +245,18 @@ mod tests {
         assert!(html.contains("Every profile can use this shared table."));
     }
 
-    /// Every type the server accepts has to be reachable from the picker, or
-    /// the web UI silently offers less than the backend does.
+    /// Fixed-scale decimal is the one intentionally gated type; enabling the
+    /// advanced control makes it reachable without removing server support.
     #[test]
     fn the_type_picker_offers_the_parameterised_and_interval_types() {
-        let html = render_builder(&page());
+        let mut state = page();
+        let html = render_builder(&state);
+
+        assert!(!html.contains(r#"<option value="decimal""#));
+        assert!(html.contains(r#"name="fixed_decimal_input""#));
+
+        state.draft.columns.fixed_decimal_input = "yes".to_string();
+        let html = render_builder(&state);
 
         for column_type in ["decimal", "duration", "period", "accounting"] {
             assert!(
@@ -273,10 +280,12 @@ mod tests {
         assert!(render_builder(&state).contains(r#"name="gtin_type_input""#));
 
         // Decimal reveals its precision and scale.
+        state.draft.columns.fixed_decimal_input = "yes".to_string();
         state.draft.columns.type_input = "decimal".to_string();
         let html = render_builder(&state);
         assert!(html.contains(r#"name="decimal_precision_input""#));
         assert!(html.contains(r#"name="decimal_scale_input""#));
+        assert!(html.contains("Advanced fixed-scale decimal"));
 
         // Money reveals its currency and rounding inputs.
         state.draft.columns.type_input = "money".to_string();
diff --git a/web/src/schema/mod.rs b/web/src/schema/mod.rs
index decde2cd..b16630a3 100644
--- a/web/src/schema/mod.rs
+++ b/web/src/schema/mod.rs
@@ -475,6 +475,10 @@ pub(crate) struct ColumnDraft {
     pub link_table_input: String,
     pub decimal_precision_input: String,
     pub decimal_scale_input: String,
+    /// Explicit opt-in for the fixed-scale decimal type. It is intentionally
+    /// absent from the normal type picker because PostgreSQL coerces values to
+    /// its declared scale and populated tables cannot later change the type.
+    pub fixed_decimal_input: String,
     pub indexing_input: String,
     pub quantity_ledger_input: String,
     pub required_input: String,
@@ -528,6 +532,7 @@ impl ColumnDraft {
             required_input: "no".to_string(),
             rounding_input: "none".to_string(),
             currency_input: "EUR".to_string(),
+            fixed_decimal_input: "no".to_string(),
             catalog,
             ..Self::default()
         }
@@ -536,7 +541,15 @@ impl ColumnDraft {
     /// The types this panel offers, which is the only place the creation-only
     /// rule shows up in the markup.
     pub(crate) fn offered_types(&self) -> Vec<String> {
-        self.catalog.offered_types(self.creating_table, self.global)
+        self.catalog
+            .offered_types(self.creating_table, self.global)
+            .into_iter()
+            .filter(|column_type| column_type != "decimal" || self.fixed_decimal_enabled())
+            .collect()
+    }
+
+    pub(crate) fn fixed_decimal_enabled(&self) -> bool {
+        self.fixed_decimal_input.trim().eq_ignore_ascii_case("yes")
     }
 
     pub(crate) fn temporal_types(&self) -> Vec<String> {
@@ -639,6 +652,9 @@ impl ColumnDraft {
             return Ok(None);
         }
         if self.catalog.is_parameterised(&column_type) {
+            if !self.fixed_decimal_enabled() {
+                return Err(crate::tr!(locale, "td-fixed-decimal-enable-first"));
+            }
             let precision = self.decimal_precision_input.trim();
             let scale = self.decimal_scale_input.trim();
             if precision.is_empty() && scale.is_empty() {
@@ -1442,6 +1458,8 @@ pub(crate) struct ColumnForm {
     #[serde(default)]
     pub decimal_scale_input: String,
     #[serde(default)]
+    pub fixed_decimal_input: String,
+    #[serde(default)]
     pub column_indexing_input: String,
     #[serde(default)]
     pub column_quantity_ledger_input: String,
@@ -1487,6 +1505,7 @@ impl ColumnForm {
             link_table_input: self.link_table_input.clone(),
             decimal_precision_input: self.decimal_precision_input.clone(),
             decimal_scale_input: self.decimal_scale_input.clone(),
+            fixed_decimal_input: self.fixed_decimal_input.clone(),
             indexing_input: self.column_indexing_input.clone(),
             quantity_ledger_input: self.column_quantity_ledger_input.clone(),
             required_input: self.column_required_input.clone(),
@@ -1755,7 +1774,10 @@ pub(crate) mod tests {
         assert!(offered.contains(&"numeric".to_string()));
         assert!(offered.contains(&"account".to_string()));
         assert!(offered.contains(&"accounting_transfer".to_string()));
-        assert!(offered.contains(&"decimal".to_string()));
+        assert!(!offered.contains(&"decimal".to_string()));
+        let mut advanced = draft();
+        advanced.fixed_decimal_input = "yes".to_string();
+        assert!(advanced.offered_types().contains(&"decimal".to_string()));
         // Families are one choice, resolved by a follow-up field.
         assert!(offered.contains(&"temporal".to_string()));
         assert!(offered.contains(&"gtin".to_string()));
@@ -1803,6 +1825,7 @@ pub(crate) mod tests {
         assert_eq!(draft.added[1].data_type, "gtin_13");
 
         draft.name_input = "weight".to_string();
+        draft.fixed_decimal_input = "yes".to_string();
         draft.type_input = "decimal".to_string();
         assert_eq!(draft.canonical_type_input(crate::i18n::Locale::default()).unwrap(), None);
         assert!(draft.show_decimal_arguments());
@@ -1843,6 +1866,7 @@ pub(crate) mod tests {
     fn decimal_arguments_follow_the_servers_rules() {
         let mut draft = draft();
         draft.name_input = "weight".to_string();
+        draft.fixed_decimal_input = "yes".to_string();
         draft.type_input = "decimal".to_string();
 
         for (precision, scale) in [("0", "0"), ("3", "5"), ("-2", "1"), ("08", "2"), ("4.5", "1")] {
@@ -1946,6 +1970,7 @@ pub(crate) mod tests {
 
         // A parameterised decimal counts, through its head.
         draft.name_input = "quantity".to_string();
+        draft.fixed_decimal_input = "yes".to_string();
         draft.type_input = "decimal".to_string();
         draft.decimal_precision_input = "12".to_string();
         draft.decimal_scale_input = "3".to_string();
diff --git a/web/templates/pages/add_table/builder.html b/web/templates/pages/add_table/builder.html
index a7028e96..0ded97e6 100644
--- a/web/templates/pages/add_table/builder.html
+++ b/web/templates/pages/add_table/builder.html
@@ -127,13 +127,22 @@
       {% if page.draft.columns.show_link_target() %}<small>{{ nav.tr("td-link-alias-hint") }}</small>{% endif %}
     </label>
     {% endif %}
+    <label>{{ nav.tr("td-fixed-decimal-access") }}
+      <select name="fixed_decimal_input" hx-post="/admin/tables/builder" hx-trigger="change"
+              hx-include="#table-form" hx-target="#builder" hx-swap="innerHTML"
+              hx-vals='{"action": "refresh"}'>
+        <option value="no" {% if !page.draft.columns.fixed_decimal_enabled() %}selected{% endif %}>{{ nav.tr("td-fixed-decimal-disabled") }}</option>
+        <option value="yes" {% if page.draft.columns.fixed_decimal_enabled() %}selected{% endif %}>{{ nav.tr("td-fixed-decimal-enabled") }}</option>
+      </select>
+      <small>{{ nav.tr("td-fixed-decimal-access-hint") }}</small>
+    </label>
     <label>{{ nav.tr("td-column-type") }}
       <select name="column_type_input" hx-post="/admin/tables/builder" hx-trigger="change"
               hx-include="#table-form" hx-target="#builder" hx-swap="innerHTML"
               hx-vals='{"action": "refresh"}'>
         <option value="">{{ nav.tr("td-choose-type") }}</option>
         {% for column_type in column_types %}
-          <option value="{{ column_type }}" {% if page.draft.columns.type_input == *column_type %}selected{% endif %}>{% if *column_type == "link" %}{{ nav.tr("td-fk-link") }}{% else %}{{ column_type }}{% endif %}</option>
+          <option value="{{ column_type }}" {% if page.draft.columns.type_input == *column_type %}selected{% endif %}>{% if *column_type == "link" %}{{ nav.tr("td-fk-link") }}{% else if *column_type == "numeric" %}{{ nav.tr("td-exact-decimal") }}{% else if *column_type == "decimal" %}{{ nav.tr("td-fixed-decimal-type") }}{% else %}{{ column_type }}{% endif %}</option>
         {% endfor %}
       </select>
     </label>
@@ -161,6 +170,10 @@
     {% endif %}
 
     {% if page.draft.columns.show_decimal_arguments() %}
+      <div class="field-note col-span-full">
+        <span class="field-label">{{ nav.tr("td-fixed-decimal-warning-title") }}</span>
+        <p class="hint">{{ nav.tr("td-fixed-decimal-warning") }}</p>
+      </div>
       <label>{{ nav.tr("td-precision") }}
         <input name="decimal_precision_input" value="{{ page.draft.columns.decimal_precision_input }}"
                inputmode="numeric" placeholder="12">
diff --git a/web/templates/pages/admin/table_definition/column_panel.html b/web/templates/pages/admin/table_definition/column_panel.html
index 154279d1..503875bd 100644
--- a/web/templates/pages/admin/table_definition/column_panel.html
+++ b/web/templates/pages/admin/table_definition/column_panel.html
@@ -29,6 +29,17 @@
     <input name="column_name_input" value="{{ page.columns.name_input }}" placeholder="issued_on">
     {% if page.columns.show_link_target() %}<small>{{ nav.tr("td-link-alias-hint") }}</small>{% endif %}
   </label>
+  <label>{{ nav.tr("td-fixed-decimal-access") }}
+    <select name="fixed_decimal_input"
+            hx-post="/admin/tables/columns/add/builder{{ page.selection.query() }}"
+            hx-trigger="change" hx-include="#column-form"
+            hx-target="#column-panel" hx-swap="innerHTML"
+            hx-vals='{"action": "refresh"}'>
+      <option value="no" {% if !page.columns.fixed_decimal_enabled() %}selected{% endif %}>{{ nav.tr("td-fixed-decimal-disabled") }}</option>
+      <option value="yes" {% if page.columns.fixed_decimal_enabled() %}selected{% endif %}>{{ nav.tr("td-fixed-decimal-enabled") }}</option>
+    </select>
+    <small>{{ nav.tr("td-fixed-decimal-access-hint") }}</small>
+  </label>
   <label>{{ nav.tr("td-column-type") }}
     <select name="column_type_input"
             hx-post="/admin/tables/columns/add/builder{{ page.selection.query() }}"
@@ -37,7 +48,7 @@
             hx-vals='{"action": "refresh"}'>
       <option value="">{{ nav.tr("td-choose-type") }}</option>
       {% for column_type in column_types %}
-        <option value="{{ column_type }}" {% if page.columns.type_input == *column_type %}selected{% endif %}>{% if *column_type == "link" %}{{ nav.tr("td-fk-link") }}{% else %}{{ column_type }}{% endif %}</option>
+        <option value="{{ column_type }}" {% if page.columns.type_input == *column_type %}selected{% endif %}>{% if *column_type == "link" %}{{ nav.tr("td-fk-link") }}{% else if *column_type == "numeric" %}{{ nav.tr("td-exact-decimal") }}{% else if *column_type == "decimal" %}{{ nav.tr("td-fixed-decimal-type") }}{% else %}{{ column_type }}{% endif %}</option>
       {% endfor %}
     </select>
   </label>
@@ -65,6 +76,10 @@
   {% endif %}
 
   {% if page.columns.show_decimal_arguments() %}
+    <div class="field-note col-span-full">
+      <span class="field-label">{{ nav.tr("td-fixed-decimal-warning-title") }}</span>
+      <p class="hint">{{ nav.tr("td-fixed-decimal-warning") }}</p>
+    </div>
     <label>{{ nav.tr("td-precision") }}
       <input name="decimal_precision_input" value="{{ page.columns.decimal_precision_input }}"
              inputmode="numeric" placeholder="12">