diff --git a/common/proto/table_definition.proto b/common/proto/table_definition.proto
index d67bedfc..c682a75e 100644
--- a/common/proto/table_definition.proto
+++ b/common/proto/table_definition.proto
@@ -108,14 +108,18 @@ message PostTableDefinitionRequest {
 // column, though, so it is free to be anything: this is where that choice is
 // made, instead of a RenameColumnAlias call afterwards.
 //
-// The ACCOUNTING_TRANSFER connectors are the exception. They are refused here
-// exactly as RenameColumnAlias refuses them.
+// Only ACCOUNTING's columns may be renamed. Renaming a generated column
+// requires its relationship to whatever generated it to be recorded, so the
+// rest of the system can find it without knowing its name; ACCOUNTING has that
+// in table_accounting_definitions, and nothing else does. The ACCOUNTING_
+// TRANSFER connectors and the PHONE and IBAN companions are refused, the
+// latter because a row write finds them by rebuilding their names from their
+// parent column's name.
 message GeneratedColumnAlias {
   // The name the backend would otherwise give the column: one of ACCOUNTING's
-  // "name", "tax_point_date", "debit", "credit" or "account", or a companion
-  // such as "work_phone_extension". Must name a column the request really
-  // generates -- an alias for anything else is rejected rather than ignored,
-  // so a typo cannot pass silently.
+  // "name", "tax_point_date", "debit", "credit" or "account". Must name a
+  // column the request really generates -- an alias for anything else is
+  // rejected rather than ignored, so a typo cannot pass silently.
   string generated_name = 1;
 
   // What the column should be called instead. Same rules as any column name.
diff --git a/common/src/proto/descriptor.bin b/common/src/proto/descriptor.bin
index 37ac7e13..5d420cab 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.table_definition.rs b/common/src/proto/komp_ac.table_definition.rs
index 7c25fc4f..75c11b64 100644
--- a/common/src/proto/komp_ac.table_definition.rs
+++ b/common/src/proto/komp_ac.table_definition.rs
@@ -56,16 +56,20 @@ pub struct PostTableDefinitionRequest {
 /// column, though, so it is free to be anything: this is where that choice is
 /// made, instead of a RenameColumnAlias call afterwards.
 ///
-/// The ACCOUNTING_TRANSFER connectors are the exception. They are refused here
-/// exactly as RenameColumnAlias refuses them.
+/// Only ACCOUNTING's columns may be renamed. Renaming a generated column
+/// requires its relationship to whatever generated it to be recorded, so the
+/// rest of the system can find it without knowing its name; ACCOUNTING has that
+/// in table_accounting_definitions, and nothing else does. The ACCOUNTING\_
+/// TRANSFER connectors and the PHONE and IBAN companions are refused, the
+/// latter because a row write finds them by rebuilding their names from their
+/// parent column's name.
 #[derive(serde::Serialize, serde::Deserialize)]
 #[derive(Clone, PartialEq, Eq, Hash, ::prost::Message)]
 pub struct GeneratedColumnAlias {
     /// The name the backend would otherwise give the column: one of ACCOUNTING's
-    /// "name", "tax_point_date", "debit", "credit" or "account", or a companion
-    /// such as "work_phone_extension". Must name a column the request really
-    /// generates -- an alias for anything else is rejected rather than ignored,
-    /// so a typo cannot pass silently.
+    /// "name", "tax_point_date", "debit", "credit" or "account". Must name a
+    /// column the request really generates -- an alias for anything else is
+    /// rejected rather than ignored, so a typo cannot pass silently.
     #[prost(string, tag = "1")]
     pub generated_name: ::prost::alloc::string::String,
     /// What the column should be called instead. Same rules as any column name.
diff --git a/server b/server
index de424f24..9984e3b2 160000
--- a/server
+++ b/server
@@ -1 +1 @@
-Subproject commit de424f245d0eced5419913bfd704d1a8d6b65b4d
+Subproject commit 9984e3b272514f51092e049465d040afb0630279
diff --git a/web/src/pages/add_table/draft.rs b/web/src/pages/add_table/draft.rs
index b459ab5d..e7024140 100644
--- a/web/src/pages/add_table/draft.rs
+++ b/web/src/pages/add_table/draft.rs
@@ -21,10 +21,6 @@ use crate::{
 /// them, and [`TableDraft::preview_rows`] is where that is explained.
 pub(crate) const ACCOUNTING_FIELD_TYPE: &str = "accounting";
 
-/// The compound type whose companions the backend refuses to rename: they are
-/// the connectors a transfer is posted through, and are looked up by name.
-pub(crate) const ACCOUNTING_TRANSFER_FIELD_TYPE: &str = "accounting_transfer";
-
 /// The virtual field the ACCOUNTING foreign key is written as. It is a column
 /// like any other once created, so it can be aliased too.
 pub(crate) const ACCOUNT_API_COLUMN: &str = "account";
@@ -229,13 +225,18 @@ impl TableDraft {
     /// The generated columns this draft would let the user rename, in the order
     /// they appear in the column list.
     ///
-    /// ACCOUNTING_TRANSFER's companions are left out: the backend refuses to
-    /// name them anything else. Everything else a definition row or a companion
-    /// type generates is a display name over a physical column, and is free.
+    /// ACCOUNTING's, and only ACCOUNTING's. A generated column can carry a name
+    /// of its own once the rest of the system can find it without that name --
+    /// which for ACCOUNTING is `table_accounting_definitions`, recording its
+    /// columns by physical name. The ACCOUNTING_TRANSFER connectors and the
+    /// PHONE and IBAN companions have no such record: a companion is found on
+    /// write by rebuilding its name from its parent's, so renaming one would
+    /// hide it from the write path. The backend refuses those, and this does
+    /// not offer what the backend refuses.
     pub(crate) fn aliasable_generated_columns(&self) -> Vec<String> {
         let mut names = Vec::new();
         for (index, column) in self.columns.added.iter().enumerate() {
-            if column.data_type == ACCOUNTING_TRANSFER_FIELD_TYPE {
+            if column.data_type != ACCOUNTING_FIELD_TYPE {
                 continue;
             }
             names.extend(
@@ -244,9 +245,7 @@ impl TableDraft {
                     .iter()
                     .map(|generated| generated.name.clone()),
             );
-            if column.data_type == ACCOUNTING_FIELD_TYPE {
-                names.push(ACCOUNT_API_COLUMN.to_string());
-            }
+            names.push(ACCOUNT_API_COLUMN.to_string());
         }
         names
     }
@@ -556,13 +555,24 @@ mod tests {
         );
     }
 
-    /// The transfer connectors are resolved by name by the posting engine, and
-    /// the backend refuses to rename them, so they are never offered.
+    /// Only ACCOUNTING's columns are offered. The transfer connectors are
+    /// resolved by name by the posting engine, and a phone or IBAN companion is
+    /// found on write by rebuilding its name from its parent's -- the backend
+    /// refuses both, so neither is offered here.
     #[test]
-    fn accounting_transfer_connectors_are_not_aliasable() {
-        let draft = draft_with_column("accounting_transfer", "accounting_transfer");
+    fn only_accounting_columns_are_aliasable() {
+        for (name, data_type) in [
+            ("accounting_transfer", "accounting_transfer"),
+            ("work_phone", "phone"),
+            ("bank_account", "iban"),
+        ] {
+            let draft = draft_with_column(name, data_type);
 
-        assert!(draft.aliasable_generated_columns().is_empty());
+            assert!(
+                draft.aliasable_generated_columns().is_empty(),
+                "`{data_type}` should offer no aliases"
+            );
+        }
     }
 
     #[test]
diff --git a/web/src/pages/add_table/state.rs b/web/src/pages/add_table/state.rs
index 90f852ff..37caad79 100644
--- a/web/src/pages/add_table/state.rs
+++ b/web/src/pages/add_table/state.rs
@@ -13,10 +13,7 @@
 
 use crate::schema::{ColumnCatalog, ColumnDraft, columns_from_rows};
 
-use super::draft::{
-    ACCOUNT_API_COLUMN, ACCOUNTING_FIELD_TYPE, ACCOUNTING_TRANSFER_FIELD_TYPE, GeneratedAlias,
-    TableDraft,
-};
+use super::draft::{ACCOUNT_API_COLUMN, ACCOUNTING_FIELD_TYPE, GeneratedAlias, TableDraft};
 
 /// The `profile_name` option meaning "create a new profile too".
 pub(crate) const NEW_PROFILE: &str = "__new__";
@@ -227,10 +224,11 @@ impl AddTablePageState {
             });
 
             // A generated column is named by the backend, but the name is a
-            // display name: it can be aliased, and the alias is applied as a
-            // rename the moment the table exists. The connectors of an
-            // ACCOUNTING_TRANSFER are the exception the backend protects.
-            let aliasable = column.data_type != ACCOUNTING_TRANSFER_FIELD_TYPE;
+            // display name, and ACCOUNTING's columns can be given one of the
+            // user's own in the request that creates them. Only ACCOUNTING's:
+            // see `TableDraft::aliasable_generated_columns` for why the other
+            // generated columns cannot be renamed at all.
+            let aliasable = column.data_type == ACCOUNTING_FIELD_TYPE;
 
             for generated in columns.generated_columns_of(index) {
                 let mut tags = vec![format!("generated by {}", column.data_type)];