A stop payment may apply to a single item or a range of checks. You provide your bank with information including your account number, the check number, payee, and the amount of the check. Your bank uses this information to identify and reject any stopped checks that are presented for payment. A bank can't place a stop payment on the basis of one piece of information, such as the amount of a check, because you could conceivably have written many checks for the same amount.
Electronic Funds Transfers
Your bank processes electronic checks by using your account and routing number to electronically transfer funds from your account. Some retailers convert paper checks into electronic checks to expedite the transfer of funds. Stop payments are designed to prevent money being transferred, as opposed to reversing transactions. You can't stop an electronic check you just authorized at the grocery store, since the funds were transferred at the time of your purchase. In the same scenario you could place a stop payment on a paper check, since it could take a few days for your bank to disburse the funds.
You can place a stop payment on an electronic transfer that is supposed to occur on a future date. For example, you can stop payment on a recurring bill that is processed as an electronic item each month. You must place the stop at least three days before the payment date. Banks typically place stop payments on the basis of an oral authorization. However, you may need to follow up with a written stop payment request within 14 days of your oral request. On recurring transfers, specify whether you want to block one installment payment or just place a blanket block on a series of payments.
Stop Payment Expiration
A stop payment remains active for six months. In theory, a payee could negotiate an electronic check after this timeframe has elapse. The six month period is significant because it's the period after which a check becomes "stale dated." Under the Uniform Commercial Code, banks don't have to honor stale dated checks. This is a recommendation rather than a legal requirement. While bankers typically refuse payment on stale dated items, it's possible your check could still be cashed.