Credit cards

Card reserves, purchases, payments and one-revision fixes.

Each card has a reserve inside the bank account that will pay it. The reserve always equals what the card owes.

A card purchase moves money from free money (or the reserve paying for it) into the card’s reserve.
Paying the card spends the reserve. Paying more than it owes puts the card into credit and its reserve follows below zero.
A card transaction written without its reserve lines is saved but flagged as unreserved until fixed.

The Credit page lists each card with what it owes, its reserve and what is still to reserve, with one-revision fixes for missing reserve lines.

Record a purchase and payment

Use Card purchase with the card, expense account, amount and source: free money or the reserve paying for it.
Check the preview includes both the card debt and the matching reserve movement.
On Credit, compare owes, reserve and still to reserve.
After the bank payment happens, use Pay a card. It consumes the reserve without reducing Cash on Hand again.

Fix mismatches carefully

Inspect unreserved transactions and add the missing reserve lines in the same transaction. A batch can fix several in one revision. If their total does not explain the difference, look for money moved directly in or out of the card reserve. Review older exclusive assertions before backdating reserve fixes; inclusive bank assertions are compatible with reserves.