Beancount: check a statement close at the next day’s opening

A Beancount balance directive checks the start of its date, before that date’s transactions. If a statement’s value is explicitly the closing balance at the end of October 31, the corresponding simple daily assertion belongs on November 1. Keep the bank’s transaction dates unchanged; moving transactions to silence a failed assertion changes the evidence.

This guide is for a Beancount user turning a statement boundary into a check. The official language documentation defines the timing and commodity scope. First establish whether your source amount is an opening or closing value: a date printed next to a balance does not settle that question on its own.

Reproduce the daily-boundary example

We ran five invented USD cases with Beancount 3.2.3, using bean-check in an isolated Python environment on October 16, 2026. No bank file, import adapter or customer ledger was used. The passing case is:

option "title" "SYNTHETIC bank cutoff demonstration"
2026-01-01 open Assets:Checking USD
2026-01-01 open Equity:Opening-Balances USD
2026-01-01 open Income:Example USD
2026-01-01 open Expenses:Example USD
2026-10-30 * "SYNTHETIC opening"
  Assets:Checking 100.00 USD
  Equity:Opening-Balances -100.00 USD
2026-10-31 * "SYNTHETIC cutoff-day receipt"
  Assets:Checking 25.00 USD
  Income:Example -25.00 USD
2026-11-01 * "SYNTHETIC next-day payment"
  Assets:Checking -5.00 USD
  Expenses:Example 5.00 USD
2026-11-01 balance Assets:Checking 125.00 USD

Save the example as cutoff.bean and run bean-check cutoff.bean with that version. The invented account has $100 before October 31, receives $25 on October 31 and pays $5 on November 1. The November 1 assertion expects $125, because it precedes the $5 payment. The balance after that payment would be $120, which is a different boundary.

Compare the five executed controls

The two failures are useful negative controls, not errors to conceal. The implementation of balance checks also distinguishes a check from an instruction to alter the account to the claimed amount.

Interpret a failure without forcing a balance

1. Confirm account identity and the source’s exact boundary. Do not use today’s available balance for a historical cutoff.
2. Check transactions on the cutoff date and the assertion date. Determine which belong before the asserted opening.
3. Check the asserted commodity. A USD assertion is not a check of a separate EUR balance.
4. Preserve the failed output, source values and unresolved rows. Investigate missing, duplicated or misdated entries before considering a correction.

These controls do not cover time-zone conversions, intraday cutoffs, liabilities or multi-currency accounting. A passing check also cannot detect two omissions that cancel each other. Combine it with row identities and the statement reconciliation process.

Keep the next-day rule conditional on the source

Use the following day for a documented end-of-day closing value. Use the stated day for a documented opening value. If the source does not establish which it is, keep the assertion decision unresolved. The deliverable is a correctly dated check with its source boundary and reproducible output, not a journal adjustment that makes an unexplained difference disappear.

Synthetic review case. The values are teaching data, not a vendor export or an import file.

For a bank source available only as PDF, download LocalExtract. It processes one PDF locally into date,description,amount CSV; review and adapt those rows for the actual destination.

Related guide: Bank statement reconciliation: balances, matches and exceptions.

Documentation for the added task checked October 16, 2026.