I had a college roommate who had difficulty with self employment income and getting a loan (he worked a paper route and wrote off mileage). His loan was to replace his car, so he was able to shop around a bit more (mortgage lending criteria doesn't seem to be as varied). I'm pretty sure all your business expenses will be excluded from your income for mortgage consideration. Even if you file your 2018 taxes without claiming mileage or other expenses, as a self employed person, the lender is likely to want multiple years of documentation for your income.