You should notify the credit union immediately of the issue. Identify by date and dollar amount the transactions that you did not authorize. The credit union will review your claim. As part of the process, the credit union may ask you to complete an affidavit of unauthorized use.
There are three possible tiers of consumer liability for unauthorized electronic fund transfers depending on the situation. A consumer may be liable for up to $50, up to $500, or an unlimited amount depending on when the unauthorized electronic fund transfer occurred.
The timing of your notice to the credit union is critical. To avoid liability for subsequent transfers, you must report to the credit union any unauthorized electronic transaction that appears on your share draft account statement within 60 calendar days of the credit union's transmittal of the statement. The credit union may hold you liable for any transactions that occurred more than 60 days after the statement was transmitted and before you notified the credit union.