Taxpayers must receive an (Online Filing Info) letter to sign up for MAT. Normally after they have registered their business with the Secretary of State, taxpayers will receive their letter within 4-6 weeks from the Alabama Department of Revenue. Once this letter is received, taxpayers need to visit our website https://myalabamataxes.alabama.gov/_/#1. In the left side of the screen you will see username, password, and logon. Beneath that you will see forgot password, forgot username, DON’T HAVE A LOG ON? REGISTER HERE. Taxpayers should click register here. Select: Business Privilege Tax. Then the taxpayer will need to provide the Account number, Sign On ID, and Access Code. This information is located on the (Online Filing Info) letter.