A GWBP charge on your bank statement is almost always an automated clearing house (ACH) withdrawal processed under a legacy Great Western Bank Payment code. Great Western Bancorp merged into First Interstate BancSystem in early 2022,1U.S. Securities and Exchange Commission. First Interstate BancSystem, Inc. – Form 8-K but the old processing descriptor still shows up on debits tied to accounts and loans that originated before the transition. If the amount matches a loan payment or fee you recognize, it’s likely legitimate. If it doesn’t, you can trace it, dispute it, and stop future pulls using the steps below.
Why the GWBP Code Still Appears
GWBP stands for Great Western Bank Payment. Customer accounts converted to First Interstate’s systems around May 2022, but the backend payment codes from the old platform didn’t necessarily change with them. Legacy processing systems preserve old descriptors to keep payment histories consistent across platforms, which is why a mortgage, auto loan, or deposit account you opened with Great Western before the merger may still pull under the original label rather than a First Interstate one.
What the Charge Is Usually For
GWBP debits are recurring financial obligations, not one-time retail purchases. The typical sources are:
- Monthly mortgage payments on a home loan originated through Great Western Bank.
- Scheduled auto or installment loan payments that predate the merger.
- Periodic deposit account fees, such as maintenance or minimum-balance charges.
These withdrawals were pre-authorized through signed agreements, so they pull automatically on a fixed schedule. A dollar amount that matches a known loan payment or fee is a strong sign the charge is yours.
How to Verify the Charge
Before you call anyone, pull three pieces of information off the statement: the exact date of the debit, the dollar amount down to the penny, and the 15-digit trace number the originating bank assigned to the ACH payment.2Federal Reserve Financial Services. FedACH Payment Trace Request Case Type The trace number is the single most useful piece of information for tracking a withdrawal back to its source. Don’t confuse it with a confirmation number or internal transaction ID; the trace number is specifically 15 digits.
If you still have old Great Western Bank loan documents or paper statements, dig them out. A matching account number will clarify almost immediately whether the GWBP code ties to an existing obligation. Then contact First Interstate Bank’s customer service line. Giving them your Social Security number or original loan ID lets their team pull the ledger and tell you which contract triggered the withdrawal.
Disputing an Unauthorized Charge
If the bank can’t connect the withdrawal to any valid agreement, or you never authorized it, Regulation E, which implements the Electronic Fund Transfer Act, gives you a defined dispute process. Notify your bank that you believe an error occurred, either by phone or in writing, and include the type of suspected error, the date, and the amount.3Consumer Financial Protection Bureau. 12 CFR 1005.11 – Procedures for Resolving Errors The bank may ask for a written, signed follow-up, but it cannot delay its investigation while waiting for that paperwork.
Once you report the error, the bank has 10 business days to investigate. It can extend the investigation to 45 calendar days, but only if it provisionally credits your account within those first 10 business days.3Consumer Financial Protection Bureau. 12 CFR 1005.11 – Procedures for Resolving Errors That provisional credit gives you full use of the disputed funds while the investigation continues. The bank must report its findings within three business days of finishing and correct any confirmed error within one business day of that determination.
The burden of proof isn’t on you. If the bank wants to hold you liable for a transfer, the bank has to establish that the transfer was authorized or that its losses resulted from your delay in reporting.4Consumer Financial Protection Bureau. 12 CFR 1005.6 – Liability of Consumer for Unauthorized Transfers
The 60-Day Deadline That Costs People Money
You must report an unauthorized electronic fund transfer within 60 days of the date your bank sent the periodic statement showing it. Miss that window and you face potential unlimited liability for unauthorized withdrawals occurring after the 60 days expire and before you finally notify the bank.4Consumer Financial Protection Bureau. 12 CFR 1005.6 – Liability of Consumer for Unauthorized Transfers The bank still has to show those later transfers wouldn’t have happened if you’d reported on time, but the exposure is real. A GWBP charge that sits unquestioned for three or four months becomes much harder to recover.
How to Stop Future GWBP Withdrawals
If the charge is tied to an obligation you’ve since paid off, or you want to revoke the authorization for any other reason, you can stop a preauthorized electronic fund transfer by notifying your bank orally or in writing at least three business days before the next scheduled payment date.5Consumer Financial Protection Bureau. 12 CFR 1005.10 – Preauthorized Transfers If you call rather than write, the bank may require written confirmation within 14 days; without it, the oral stop-payment order expires.6eCFR. 12 CFR 1005.10 – Preauthorized Transfers
It’s also worth contacting the company or institution pulling the funds to formally revoke their authorization, so there’s a paper trail on both ends. Your bank may charge a stop-payment fee that typically runs from $0 to $35 depending on the institution and account type. Some banks waive it for premium accounts or for recurring debit cancellations.
One warning: if the underlying loan or account is still active and you stop the withdrawals without resolving the debt, you can end up in default. A stop-payment order is a mechanical step. It doesn’t cancel the obligation. Make sure any account tied to the GWBP charge is fully paid or formally closed before you treat the withdrawals as something that shouldn’t happen.