diff --git a/client/components/BillModal.jsx b/client/components/BillModal.jsx
index 27ef6c2..689df6a 100644
--- a/client/components/BillModal.jsx
+++ b/client/components/BillModal.jsx
@@ -1043,11 +1043,44 @@ export default function BillModal({ bill, initialBill, categories, onClose, onSa
             {/* Bank Matching Rules */}
             {!isNew && (
               <div className="mt-4 rounded-lg border border-border/60 bg-background/35">
-                <div className="border-b border-border/50 px-3 py-2.5">
-                  <p className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">Bank matching rules</p>
-                  <p className="mt-0.5 text-[11px] text-muted-foreground/70">
-                    Transactions whose description contains these patterns are automatically imported as payments.
-                  </p>
+                <div className="flex items-center justify-between gap-3 border-b border-border/50 px-3 py-2.5">
+                  <div>
+                    <p className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">Bank matching rules</p>
+                    <p className="mt-0.5 text-[11px] text-muted-foreground/70">
+                      Transactions whose description contains these patterns are automatically imported as payments.
+                    </p>
+                  </div>
+                  {sourceBill?.has_merchant_rule && (
+                    <Button
+                      type="button"
+                      size="sm"
+                      variant="outline"
+                      className="shrink-0 gap-1.5 text-xs"
+                      disabled={syncingPayments}
+                      title="Scan unmatched bank transactions and import any matching payments for this bill"
+                      onClick={async () => {
+                        setSyncingPayments(true);
+                        try {
+                          const result = await api.syncBillSimplefinPayments(sourceBill.id);
+                          if (result.added > 0) {
+                            toast.success(`${result.added} payment${result.added !== 1 ? 's' : ''} imported from bank history.`);
+                            loadLinkedTransactions?.();
+                            refetch?.();
+                          } else {
+                            toast.info('No new matching transactions found.');
+                          }
+                        } catch (err) {
+                          toast.error(err.message || 'Sync failed.');
+                        } finally {
+                          setSyncingPayments(false);
+                        }
+                      }}
+                    >
+                      {syncingPayments
+                        ? <><Loader2 className="h-3.5 w-3.5 animate-spin" />Syncing…</>
+                        : <><RefreshCw className="h-3.5 w-3.5" />Sync</>}
+                    </Button>
+                  )}
                 </div>
                 <div className="px-3 py-3">
                   <BillMerchantRules
diff --git a/services/billMerchantRuleService.js b/services/billMerchantRuleService.js
index 24d6719..1ee7e51 100644
--- a/services/billMerchantRuleService.js
+++ b/services/billMerchantRuleService.js
@@ -1,6 +1,7 @@
 'use strict';
 
 const { normalizeMerchant } = require('./subscriptionService');
+const { computeBalanceDelta } = require('./billsService');
 
 // Persist a merchant→bill rule so future synced transactions auto-match.
 function addMerchantRule(db, userId, billId, merchant) {
@@ -48,10 +49,12 @@ function applyMerchantRules(db, userId) {
 
   if (txRows.length === 0) return { matched: 0 };
 
+  const getBill      = db.prepare('SELECT current_balance, interest_rate FROM bills WHERE id = ? AND deleted_at IS NULL');
   const insertPayment = db.prepare(`
-    INSERT OR IGNORE INTO payments (bill_id, amount, paid_date, payment_source, transaction_id)
-    VALUES (?, ?, ?, 'auto_match', ?)
+    INSERT OR IGNORE INTO payments (bill_id, amount, paid_date, payment_source, transaction_id, balance_delta)
+    VALUES (?, ?, ?, 'provider_sync', ?, ?)
   `);
+  const updateBalance = db.prepare("UPDATE bills SET current_balance = ?, updated_at = datetime('now') WHERE id = ?");
   const updateTx = db.prepare(`
     UPDATE transactions
     SET matched_bill_id = ?, match_status = 'matched', updated_at = datetime('now')
@@ -73,10 +76,18 @@ function applyMerchantRules(db, userId) {
       const paidDate = tx.posted_date || (tx.transacted_at ? String(tx.transacted_at).slice(0, 10) : null);
       if (!paidDate) continue;
 
-      const amount = Math.round(Math.abs(tx.amount)) / 100;
-      insertPayment.run(rule.bill_id, amount, paidDate, tx.id);
-      updateTx.run(rule.bill_id, tx.id, userId);
-      matched++;
+      const amount   = Math.round(Math.abs(tx.amount)) / 100;
+      // Read bill fresh so sequential matches for the same bill chain correctly
+      const bill     = getBill.get(rule.bill_id);
+      const balCalc  = bill ? computeBalanceDelta(bill, amount) : null;
+
+      const result = insertPayment.run(rule.bill_id, amount, paidDate, tx.id, balCalc?.balance_delta ?? null);
+      if (result.changes > 0) {
+        // Only update balance and mark matched if the payment was actually inserted
+        if (balCalc) updateBalance.run(balCalc.new_balance, rule.bill_id);
+        updateTx.run(rule.bill_id, tx.id, userId);
+        matched++;
+      }
     }
   })();
 
@@ -126,10 +137,12 @@ function syncBillPaymentsFromSimplefin(db, userId, billId) {
 
   if (txRows.length === 0) return { added: 0 };
 
+  const getBill      = db.prepare('SELECT current_balance, interest_rate FROM bills WHERE id = ? AND deleted_at IS NULL');
   const insertPayment = db.prepare(`
-    INSERT OR IGNORE INTO payments (bill_id, amount, paid_date, payment_source, transaction_id)
-    VALUES (?, ?, ?, 'auto_match', ?)
+    INSERT OR IGNORE INTO payments (bill_id, amount, paid_date, payment_source, transaction_id, balance_delta)
+    VALUES (?, ?, ?, 'provider_sync', ?, ?)
   `);
+  const updateBalance = db.prepare("UPDATE bills SET current_balance = ?, updated_at = datetime('now') WHERE id = ?");
   const updateTx = db.prepare(`
     UPDATE transactions
     SET matched_bill_id = ?, match_status = 'matched', updated_at = datetime('now')
@@ -145,10 +158,16 @@ function syncBillPaymentsFromSimplefin(db, userId, billId) {
       if (!matches) continue;
       const paidDate = tx.posted_date || (tx.transacted_at ? String(tx.transacted_at).slice(0, 10) : null);
       if (!paidDate) continue;
-      const amount = Math.round(Math.abs(tx.amount)) / 100;
-      insertPayment.run(billId, amount, paidDate, tx.id);
-      updateTx.run(billId, tx.id, userId);
-      added++;
+      const amount  = Math.round(Math.abs(tx.amount)) / 100;
+      const bill    = getBill.get(billId);
+      const balCalc = bill ? computeBalanceDelta(bill, amount) : null;
+
+      const result = insertPayment.run(billId, amount, paidDate, tx.id, balCalc?.balance_delta ?? null);
+      if (result.changes > 0) {
+        if (balCalc) updateBalance.run(balCalc.new_balance, billId);
+        updateTx.run(billId, tx.id, userId);
+        added++;
+      }
     }
   })();
 
diff --git a/services/encryptionService.js b/services/encryptionService.js
index ee45355..a8b75ab 100644
--- a/services/encryptionService.js
+++ b/services/encryptionService.js
@@ -10,26 +10,11 @@ const HKDF_INFO  = 'bill-tracker-token-encryption-v1';
 // Prefix that identifies ciphertext produced with HKDF key derivation.
 const V2_PREFIX  = 'v2:';
 
-let _warnedAutoKey = false;
-
-// Returns the raw key material (IKM) without derivation — shared by both paths.
+// Returns the raw key material (IKM) without derivation.
+// The encryption key is auto-generated on first run and stored in the database
+// under `_auto_encryption_key`. No environment variable required — all settings
+// live in the app. The key is created once and reused across restarts.
 function getIkm() {
-  const envRaw = process.env.TOKEN_ENCRYPTION_KEY || '';
-  if (envRaw) {
-    const buf = Buffer.from(envRaw, 'utf8');
-    if (buf.length < 32) throw new Error('TOKEN_ENCRYPTION_KEY must be at least 32 bytes');
-    return buf;
-  }
-
-  if (!_warnedAutoKey) {
-    _warnedAutoKey = true;
-    console.warn(
-      '[security] TOKEN_ENCRYPTION_KEY is not set. Using an auto-generated key ' +
-      'stored in the database alongside the encrypted data. Set TOKEN_ENCRYPTION_KEY ' +
-      'as an environment variable to keep the key separate from the data it protects.',
-    );
-  }
-
   // Lazy-require to avoid circular dependency at module load time
   const { getSetting, setSetting } = require('../db/database');
   let stored = getSetting('_auto_encryption_key');