# Count each payment once

AT Learn practice example.

1. Match by document.
2. Remove duplicates by payment ID, not amount.
3. Count #901 once.
4. Register total: RUB 25,500. Unique payments: RUB 28,000.
5. B-24 shortfall: RUB 500. Separately, RUB 3,000 has no document. An aggregate difference does not replace line-by-line review.