1. Find the deposit. Go to Bookkeeping > Chart of Accounts, open the bank account's register, and locate the deposit by date or amount. You can also search for it from + New > Bank Deposit.
2. Open it. Click the deposit line to expand it, then click into the row to open the full deposit screen.
3. Change what's actually wrong. Add or remove a payment line pulled from Undeposited Funds, correct an amount on an Add funds to this deposit line, fix the account a non-payment line posted to, or adjust the date. You don't need to touch anything that's already right.
4. Watch the running total as you edit. The total at the bottom needs to keep matching your actual bank deposit after the change; if you adjust a line's amount, recheck that the total still ties out before moving on.
5. Save it. Click Save and close. This updates the existing deposit record in place; it doesn't create a second one alongside it.
6. Check reconciliation status first if the deposit might already be reconciled. Editing the amount or date on a deposit that's part of a closed, reconciled period throws that period's balance out the same way deleting it would. If the month's already closed, loop in whoever owns the reconciliation before saving.