How do I file a 1040 for my brother in prison for a stimulus payment?

A tax return can be filed for your brother by using the power of attorney form. Your brother must file Form 2848 with the IRS- it will authorize you to deal with his taxes. Here is the form and it's instructions:

• Form 2848
• Instructions for Form 2848

He may be allowed to file this right from prison and email you a copy. Once received, you can file his return online just like you would prepare your own.

If you are e-filing your tax return, then mail your statements along with Form 8453 to (check the box for Form 2848): 

Internal Revenue Service

Attn: Shipping and Receiving, 0254 

Receipt and Control Branch 

Austin, TX 73344-0254

If you need a blank Form 8453, you can download this pdf, enter your address information and check the box for Form 8949 (this form is really just a cover sheet).