In addition to filling out an application, you must provide the following documents when applying for an apartment:

If you are working for a company: 1) Letter of employment stating your position, salary and length of employment; 2) Two most recent pay stubs; 3) A recent bank statement; and 4) A copy of your photo ID.  Occasionally landlords ask for copies of canceled rent checks and/or a letter from you current landlord.

If you are self-employed: You must provide the aforementioned paperwork, but instead of a letter of employment and pay stubs, you will be required to provide a copy of the first two pages of your tax returns for the past two years.   

These requirements apply not only to applicants but also to their guarantors, though guarantors are not required to provide any information on their current landlord.