Overview
If you notice a lease balance is off, it's usually because a charge or a payment was entered incorrectly. Which article you need depends on what you're trying to fix:
An incorrect charge: See Edit a Charge on a Lease.
An incorrect payment that hasn't been deposited yet: You can edit it directly on the lease's Transactions tab.
An incorrect payment that's already been deposited: See Edit a Lease Payment That Has Already Been Deposited, since you'll need to remove the bank deposit first before you can make changes.
Tip: After editing a payment, you'll need to redeposit it. See Manually Record a Bank Deposit for instructions.