To reconcile a bank account you compare what your books say happened to what the bank statement says happened, then chase down any difference until the two agree to the cent. It is the single check that proves your records match reality, and it is the reason an accountant will or won’t trust your numbers. Here is how to do it by hand, what usually causes a mismatch, and how an AI agent runs the same reconciliation in LedgerMCP.
What is a bank reconciliation, and why does it matter?
Your books are your own record of every dollar in and out. The bank statement is an independent record of the same account. If your bookkeeping is complete and correct, the two should end the month at exactly the same balance. Reconciling is the act of confirming that they do.
This matters more than any single report, because reconciliation is what catches the things you didn’t know were wrong: a payment you forgot to record, a charge posted twice, a bank fee you never entered, a typo in an amount, or in the worst case a transaction you never authorized. A profit and loss statement built on unreconciled books is a confident guess. A reconciled month is proof.
How to reconcile a bank statement by hand
The manual process is the same everywhere, whether you use a spreadsheet or paper:
- Get the statement. Pull the official statement for the account and the period, usually a calendar month. Note its ending balance and ending date.
- Start from the last reconciled point. Begin with the ending balance from last month’s reconciliation. If this is your first one, start from the account’s opening balance.
- Tick off cleared items. Go line by line down the statement and match each deposit and each withdrawal to the same transaction in your books. Check off both sides as you find them. A transaction that appears on the statement has “cleared” the bank.
- List what hasn’t cleared. Anything in your books that the statement doesn’t show yet is outstanding: a check you wrote that hasn’t been cashed, a deposit in transit. Set those aside; they are not errors, just timing.
- Compare the ending balances. Take the statement ending balance, subtract outstanding withdrawals, add outstanding deposits, and see whether it equals your book balance. If it does, you’re done. If it doesn’t, you have a difference to investigate.
What causes the difference?
When the two numbers don’t match, the culprit is almost always one of a short list:
- Outstanding checks or deposits. Pure timing. The item is in your books but hasn’t hit the bank yet. These resolve themselves next month.
- Missing transactions. Something cleared the bank that you never recorded, a fee, an autopay, a card charge. This is the most common real gap.
- Bank fees and interest. Service charges, wire fees, and interest earned show up on the statement first and are easy to forget to book.
- Duplicates. The same transaction entered twice, often when an import overlaps a manual entry. This makes your balance drift by the amount of the duplicate.
- Amount or date errors. A $52 charge typed as $25, or a transaction dated to the wrong month. Small typos, real mismatches.
The difference itself is a clue. If the gap equals a round number you recognize, you’re probably looking at one missing transaction. If it’s the exact amount of a charge that appears twice, you have a duplicate.
How often should you reconcile?
Once a month, right after the statement closes, for every account you use, checking, savings, and each credit card. Monthly is the sweet spot: frequent enough that a mismatch points at just a few weeks of activity, rare enough that it isn’t a chore. Reconciliation is the backbone of a month-end close, the step that catches whatever the earlier steps missed before you lock the period.
How an AI agent reconciles in LedgerMCP
LedgerMCP has bank reconciliation built in, and because it exposes an MCP server, you can hand the whole job to an AI assistant like Claude or ChatGPT. You review the result; the agent does the matching. There are two modes:
- Whole-balance mode. You give it the statement’s ending balance and date. It compares that to the balance computed from your postings and tells you immediately whether the account ties.
- Worksheet mode. You check off cleared rows one by one, the classic tick-and-tie, when you want to walk the statement line by line.
Either way, when it ties, LedgerMCP saves a proof of the reconciliation for that period, so a closed month stays closed and nobody re-litigates it later. When it doesn’t tie, you don’t get a shrug. You get a ranked list of suspects: unposted rows that would close the gap, and possible duplicates that would open one. That list turns “I’m off by $84” into “here are the three transactions most likely to explain it.”
Because LedgerMCP is real double-entry accounting where every posting is immutable and balances are computed from the postings themselves, a reconciled balance can’t quietly change after the fact. Corrections happen as new, visible entries, never as silent edits.
Quick answers
What if my bank account won’t reconcile?
Work the difference, not the whole statement. Look for a missing transaction equal to the gap, a duplicate, or a typo where an amount is transposed. In LedgerMCP the suspect list points you straight at the likely rows. Fix or add the offending transaction and re-run.
How often should I reconcile a bank account?
Monthly, as soon as each statement closes, for every bank and card account. Doing it any less often just means a bigger pile to search through when something is off.
Is reconciling the same as categorizing transactions?
No. Categorizing decides what a transaction is (rent, supplies, income) and is covered in how to categorize business expenses. Reconciling confirms that your recorded transactions, whatever their categories, match the bank. You categorize first, then reconcile.
Do I need bank statements to reconcile?
Yes. The official statement is the independent record you’re checking against. You can reconcile from a PDF statement, from a live bank feed, or from the ending balance printed on it, but you do need that outside source of truth.