diff --git a/db/database.js b/db/database.js
index d17a81b..44cced4 100644
--- a/db/database.js
+++ b/db/database.js
@@ -701,6 +701,21 @@ function reconcileLegacyMigrations() {
         }
         console.log('[migration] users: snowball_extra_payment column added');
       }
+    },
+    {
+      version: 'v0.50',
+      description: 'payments: balance_delta column for debt payoff tracking',
+      check: function() {
+        const cols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
+        return cols.includes('balance_delta');
+      },
+      run: function() {
+        const cols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
+        if (!cols.includes('balance_delta')) {
+          db.exec('ALTER TABLE payments ADD COLUMN balance_delta REAL');
+        }
+        console.log('[migration] payments: balance_delta column added');
+      }
     }
   ];