Applying for an apartment? All individuals over the age of 18 MUST fill out a separate application if they will be living on the property.Your landlord may ask for an income verification letter or proof of income letter. Here's how to write that letter of employment for renting. And if they refuse at first, they will often accept if you offer to pay the first few months of rent in advance. Pay stubs are the most common documentation used. What's in a proof of income letter? This letter will have your salary and contact information for your employer so your landlord can verify all of the information. A sample letter offering a job contingent upon the results of a background check or other criteria. Learn how to write a proof of income letter with our stepbystep guide and use our fillintheblanks template as an example.