Most landlords will require that both parties apply and that both parties sign the lease. Credit evaluation and verification of both will matter. Landlords want consistency, are looking for a solid track record and the ability to pay. The question is always what if one party leaves early. Will the remaining party be responsible and have the ability to adhere to the terms of the lease.
As a guideline, landlords typically want 2.5 times the combined gross income of all people who will sign the lease. They usually score applicants based on credit history, rental history, employment, income, criminal & eviction history.
Make sure you both have a solid understanding of your lease obligations and responsibilities, but even more so, an understanding between each other.