diff --git a/docs/IMPLEMENTATION_PLAN.md b/docs/IMPLEMENTATION_PLAN.md
index 7af3e30..6ef4f77 100644
--- a/docs/IMPLEMENTATION_PLAN.md
+++ b/docs/IMPLEMENTATION_PLAN.md
@@ -1710,7 +1710,7 @@ public enum CashBookEntryType { Income = 0, Expense = 1 }
 | ✓ | K9 | Application | Category Seeder | 1 |
 | ✓ | K10 | Application | Day Close Integration | 1 |
 | ✓ | K11 | Web | Fluxor CategoryState | 4 |
-| ☐ | K12 | Web | Fluxor CashBookState | 4 |
+| ✓ | K12 | Web | Fluxor CashBookState | 4 |
 | ☐ | K13 | Web | CashBook UI | 3 |
 | ☐ | K14 | Web | Categories UI | 2 |
 | ☐ | K15 | Web | Reports UI | 2 |