You have a $10 balance in your checking account and you write a check for $12, what is your new balance?

You have a negative balance of -$2

A transaction that brings your account into a negative balance is called an overdraft. A transaction that would bring your account negative but the bank returns unpaid is called non sufficient funds or insufficient funds transaction. Banks may charge a fee for either an overdraft or a returned unpaid transaction.

I hope this helped