diff --git a/docs/IMPLEMENTATION_PLAN.md b/docs/IMPLEMENTATION_PLAN.md
index 6ef4f77..45ac0b5 100644
--- a/docs/IMPLEMENTATION_PLAN.md
+++ b/docs/IMPLEMENTATION_PLAN.md
@@ -1711,7 +1711,7 @@ public enum CashBookEntryType { Income = 0, Expense = 1 }
 | ✓ | K10 | Application | Day Close Integration | 1 |
 | ✓ | K11 | Web | Fluxor CategoryState | 4 |
 | ✓ | K12 | Web | Fluxor CashBookState | 4 |
-| ☐ | K13 | Web | CashBook UI | 3 |
+| ✓ | K13 | Web | CashBook UI | 3 |
 | ☐ | K14 | Web | Categories UI | 2 |
 | ☐ | K15 | Web | Reports UI | 2 |
 | ☐ | K16 | Application | Excel Export (ClosedXML) | 3 |