Reconciling is comparing what your books say happened in a bank account against what the bank says happened, until the two agree. Every transaction on the statement is in your books, every transaction in your books is on the statement, and the closing balances match.
It is the closest thing bookkeeping has to a proof. Everything else in your accounts is your own record of events; this is the one place an outside party independently confirms it.
What it actually catches
Not fraud, usually. Ordinary things, and all of them change your numbers:
- A payment you forgot to record. Your books say you have more money than you do.
- A duplicate. The same expense entered twice, quietly doubling a cost.
- A wrong amount. $54.00 typed as $45.00 — the books still balance internally, because both sides were wrong together. Only the bank catches it.
- Bank fees and interest you never knew about until you looked.
- A subscription you stopped using but never stopped paying.
Notice that double-entry cannot find most of these. A transposed amount debits and credits the same wrong number, so the books balance perfectly and are wrong. Reconciling is the check that catches what internal consistency cannot.
Why it matters more for marketplace sellers
You have money in more than one place. Cash in the bank, and money marketplaces are holding.
Reconciling the bank proves your cash is right. Comparing your marketplace receivable against what the marketplace says it is holding does the same job for the rest. Between them they cover everything you own — and the second check is the one that catches a fee or refund that never made it into your books.
How often
Monthly, when the statement closes, is the normal rhythm. Weekly is better if you have a lot of volume, because a discrepancy found seven days later takes minutes to explain and one found seven months later can be genuinely unfindable.
The cost of falling behind is not linear. It compounds.
Once it is reconciled, leave it alone
After a period is reconciled and agrees with the bank, changing a transaction inside it silently breaks that agreement — the closing balance you proved no longer matches, and nothing tells you.
SalesImporter locks reconciled transactions for exactly that reason. If something genuinely needs correcting, the right move is an adjusting entry in the current period rather than editing history: it keeps the trail of what was known and when, which is what an accountant or an auditor will look for.
The mindset that makes it quick
Do not try to make it balance. Try to find out why it does not.
A difference is information — it has a cause, and the cause is usually one specific transaction. Chasing the cause takes minutes and teaches you something. Plugging the gap with an adjustment to make the number look right destroys the only check you had.