diff --git a/supabase/functions/buildium-gl-sync/index.ts b/supabase/functions/buildium-gl-sync/index.ts
index 7f525ef..afa683b 100644
--- a/supabase/functions/buildium-gl-sync/index.ts
+++ b/supabase/functions/buildium-gl-sync/index.ts
@@ -164,7 +164,7 @@ Deno.serve(async (req) => {
     // ---- Companies in scope: Buildium-managed = has buildium_gl entries ----
     const { data: companies, error: cErr } = await supabase
       .from("companies")
-      .select("id, name, association_id, acmacc_sync_config")
+      .select("id, name, association_id, acmacc_sync_config, gl_auto_post")
       .not("association_id", "is", null);
     if (cErr) throw cErr;
 
@@ -331,11 +331,23 @@ Deno.serve(async (req) => {
         // flagged for the GL Account Map UI, and re-pulled once mapped.
         const { data: localAccounts, error: aErr } = await supabase
           .from("accounts")
-          .select("id, type")
+          .select("id, type, is_bank, name")
           .eq("company_id", company.id);
         if (aErr) throw aErr;
         const localById = new Map<string, any>();
-        for (const a of localAccounts || []) localById.set(a.id, a);
+        const bankIds = new Set<string>();
+        const acctNameById = new Map<string, string>();
+        for (const a of localAccounts || []) {
+          localById.set(a.id, a);
+          acctNameById.set(a.id, a.name);
+          if (a.is_bank) bankIds.add(a.id);
+        }
+        // Import-mode companies (gl_auto_post=false) don't post Banking entries
+        // to the GL; their bank registers are fed only from the GL pull. Mirror
+        // each inserted bank line into accounting.transactions so the registers
+        // and reconciliation stay current. gl_managed companies skip this — the
+        // register is their source of truth and post_transaction_gl drives the GL.
+        const materializeRegister = company.gl_auto_post === false;
 
         const { data: linkRows, error: lkErr } = await pub
           .from("buildium_gl_account_links")
@@ -427,15 +439,48 @@ Deno.serve(async (req) => {
               }
               throw jeErr;
             }
-            const { error: lErr } = await supabase
+            const { data: insertedLines, error: lErr } = await supabase
               .from("journal_entry_lines")
-              .insert(lineRows.map((l) => ({ ...l, journal_entry_id: je.id })));
+              .insert(lineRows.map((l) => ({ ...l, journal_entry_id: je.id })))
+              .select("id, account_id, debit, credit");
             if (lErr) {
               // Don't leave a headerless entry behind.
               await supabase.from("journal_entries").delete().eq("id", je.id);
               throw lErr;
             }
             companyResult.inserted += 1;
+
+            // ---- Materialize bank register rows (import-mode companies) ----
+            if (materializeRegister) {
+              const lines = insertedLines || [];
+              const offsetIds = [...new Set(lines.filter((l: any) => !bankIds.has(l.account_id)).map((l: any) => l.account_id))];
+              const offsetId = offsetIds.length === 1 ? offsetIds[0] : null;
+              const offsetName = offsetId ? (acctNameById.get(offsetId) ?? null) : null;
+              const regRows = lines
+                .filter((l: any) => bankIds.has(l.account_id))
+                .map((l: any) => {
+                  const moneyIn = Number(l.debit) > 0; // bank debit = deposit (money in)
+                  return {
+                    company_id: company.id,
+                    account_id: l.account_id,
+                    date: tx.date || today,
+                    description: tx.description || "Buildium GL",
+                    amount: moneyIn ? Number(l.debit) : Number(l.credit),
+                    type: moneyIn ? "credit" : "debit", // register: credit = deposit, debit = withdrawal
+                    category: offsetName,
+                    coa_account_id: offsetId,
+                    cleared: false,
+                    journal_entry_line_id: l.id,
+                  };
+                });
+              if (regRows.length > 0) {
+                const { error: regErr } = await supabase
+                  .from("transactions")
+                  .upsert(regRows, { onConflict: "journal_entry_line_id", ignoreDuplicates: true });
+                if (regErr) companyResult.errors.push(`register materialize (tx ${txId}): ${regErr.message}`);
+                else companyResult.register_rows = (companyResult.register_rows ?? 0) + regRows.length;
+              }
+            }
           } catch (e: any) {
             companyResult.errors.push(`tx ${txId}: ${e?.message || String(e)}`);
           }
diff --git a/supabase/migrations/20260613120000_transactions_journal_entry_line_link.sql b/supabase/migrations/20260613120000_transactions_journal_entry_line_link.sql
new file mode 100644
index 0000000..89d477d
--- /dev/null
+++ b/supabase/migrations/20260613120000_transactions_journal_entry_line_link.sql
@@ -0,0 +1,12 @@
+-- Link bank-register transactions back to the GL line that produced them, so
+-- the Buildium GL pull can materialize register rows idempotently for
+-- import-mode companies (gl_auto_post = false). NULL = manually-entered or
+-- legacy register row with no GL source. NULLs are distinct, so many unlinked
+-- rows coexist; the unique index only prevents materializing the same GL line
+-- into the register twice (and is usable as an ON CONFLICT target).
+alter table accounting.transactions
+  add column if not exists journal_entry_line_id uuid
+  references accounting.journal_entry_lines(id) on delete set null;
+
+create unique index if not exists transactions_jel_id_uidx
+  on accounting.transactions(journal_entry_line_id);