When a statement period is not the calendar month, post each transaction by its own date, not by the statement it sits on. Lines after the last day of the month wait for next month's close. Then prove the month with a balance calculated for its last day, since no statement prints one.
Why is a client's statement period not the calendar month?
Banks set statement cycles to suit their own processing, so a cycle can end on any day. Accounts opened mid-month often keep the opening day as their cycle date, and banks may spread cycle dates across the month to balance their workload. Credit cards nearly always close mid-month. None of this is wrong; it just does not match the books.
The books, by contrast, almost always close on the last day of the month. Reports, sales tax returns and the client's own expectations all run on calendar months. That leaves the bookkeeper to translate. One statement covering March 16 to April 15 contains half of March and half of April, and each half belongs to a different close.
A quick way to see the problem for a new client is to list every account with its cycle end date. A client with checking on the last day, savings on the 20th and a card on the 12th has three different cutoffs to manage each month. Keeping that list current matters more as accounts are added; bookkeeping for multiple bank accounts covers running every account through one close in a fixed order.
Splitting a mid-month statement period at the cutoff
Splitting a statement means assigning each line to a month by its posting date, then carrying the lines after the cutoff forward. The statement itself stays whole in the file. Only the posting is divided: March lines go into the March close, and April lines wait for April, where they join the first half of the next statement.
A worked example
The figures below are made up. The statement covers March 16 to April 15.
| Date | Description | Debit | Credit | Running balance | Month |
|---|---|---|---|---|---|
| Mar 16 | Opening balance | 8,200.00 | |||
| Mar 19 | Customer deposit | 3,100.00 | 11,300.00 | March | |
| Mar 27 | Supplier payment | 1,940.00 | 9,360.00 | March | |
| Mar 31 | Monthly service fee | 15.00 | 9,345.00 | March | |
| Apr 2 | Rent | 2,600.00 | 6,745.00 | April | |
| Apr 11 | Customer deposit | 2,450.00 | 9,195.00 | April | |
| Apr 15 | Closing balance | 9,195.00 |
March gets three lines, and April gets two. The running balance after the March 31 fee, 9,345.00, is the bank's balance for the last day of March. That is the number the March close must agree with.
When you post this way, the statement is converted once, in full, and the lines are filtered by date at posting time. Converting a statement twice to get each half invites duplicates. In AutoBankConvert, the whole statement is converted once and checked against its own opening and closing balances, so the full file stays the source and the split happens only when you post.
Which balance proves a month with a mid-month statement cycle?
The balance that proves the month is the bank balance at the end of the last day of the month, worked out from the statement. Read it from the running balance on the last line dated on or before month end, or, without running balances, apply each line to the opening balance up to the cutoff.
Reconcile the ledger to that calculated balance, not to either statement's printed closing figure. In the example above, the March close reconciles to 9,345.00. Write down how you got it, with the statement name and the line you stopped at, so a reviewer can follow the same path.
A statement without running balances needs one more step. Add the March lines to the opening balance by hand or in a spreadsheet, then check that the April lines carry that figure to the printed closing balance. If both halves add up, the split is complete and nothing has been dropped at the seam.
Asking the bank to move the statement cycle to month end
Some banks will move an account's statement cycle to the last day of the month on request, and some will not. It is worth asking for a client's main operating account, because a month-end cycle removes the split work for good. For a rarely used account, the split takes minutes and may not justify the call.
If the client agrees to ask, give them the exact request: a statement cycle ending on the last calendar day of each month, starting with the next cycle. Expect one short transition statement while the cycle moves. Treat it like any other statement and check that its opening balance matches the prior closing balance.
Handling a cutoff by hand every month is a small task that grows when it is repeated across a client list. If you are deciding which recurring steps to systematise first, the guide to automating bookkeeping without losing control is a good place to weigh them.
Cutoff errors when two statements overlap one month
The errors happen at the seam, where one statement's last days and the next statement's first days fall in the same month. A line can be posted twice, once from each side, or skipped because each close assumed the other caught it. Both errors leave the month out of balance with the calculated figure.
The common patterns are these:
- Double posting. The March close posts the whole March 16 to April 15 statement, and the April close posts it again for its April lines.
- A skipped tail. The April close starts from the April 16 statement and never picks up April 1 to 15.
- A date mismatch. A transaction dated March 31 posts on April 1, and the bookkeeper uses one date for the split and the other for the ledger.
Pick one date rule per client, usually the posting date because it drives the bank's running balance, and use it everywhere. Mixed personal and business lines make the seam harder to read; if that is the case, separate them first using the steps for commingled personal and business transactions.
Across a client list, it helps to record each account's cycle date in your task tracker so the April close knows to wait for the April 15 statement. Task management for multiple bookkeeping clients covers keeping those dates in one place.