diff --git a/backend/app.py b/backend/app.py
index 93a0098..3394beb 100644
--- a/backend/app.py
+++ b/backend/app.py
@@ -1006,12 +1006,35 @@ def recalc_invoice_totals(invoice_id):
         conn.close()
         return
 
-    cursor.execute("""
-        SELECT COALESCE(SUM(payment_amount), 0) AS total_paid
-        FROM payments
-        WHERE invoice_id = %s
-          AND payment_status = 'confirmed'
-    """, (invoice_id,))
+    invoice_currency = str(invoice.get("currency_code") or "CAD").upper()
+
+    if invoice_currency == "CAD":
+        cursor.execute("""
+            SELECT COALESCE(SUM(
+                CASE
+                    WHEN UPPER(COALESCE(payment_currency, '')) = 'CAD'
+                        THEN payment_amount
+                    ELSE COALESCE(cad_value_at_payment, 0)
+                END
+            ), 0) AS total_paid
+            FROM payments
+            WHERE invoice_id = %s
+              AND payment_status = 'confirmed'
+        """, (invoice_id,))
+    else:
+        cursor.execute("""
+            SELECT COALESCE(SUM(
+                CASE
+                    WHEN UPPER(COALESCE(payment_currency, '')) = %s
+                        THEN payment_amount
+                    ELSE 0
+                END
+            ), 0) AS total_paid
+            FROM payments
+            WHERE invoice_id = %s
+              AND payment_status = 'confirmed'
+        """, (invoice_currency, invoice_id))
+
     row = cursor.fetchone()
 
     total_paid = to_decimal(row["total_paid"])