To be considered for certification under the rules of AZ POST, you must complete this application and RETURN IT TO THE DEPARTMENT TO WHICH YOU ARE APPLYING. II. STEP 1: USING BLACK INK ONLY, Fill out the "Civil Cover Sheet." â–« Write in "Maricopa" as the county. Learn how to write a proof of income letter with our stepbystep guide and use our fillintheblanks template as an example. You receive an EIN Confirmation Letter once you have completed the Employer Identification Number (EIN) application on the IRS website. First, find out why your tenant needs a proof of residency letter. STEP 1: USING BLACK INK ONLY, Fill out the "Civil Cover Sheet. " â–« Write in "Maricopa" as the county. Template instructions are outlined in the Employee Details step. A landlord will look to confirm the company you work for and their contact information.