I'm starting a new job next week. It's more pay than my current job and still a W-2. My husband and I are looking to buy our first rental property. When is the best time to get preapproved for a mortgage?

Originally posted by @Alyssa Paros :

I'm starting a new job next week. It's more pay than my current job and still a W-2. My husband and I are looking to buy our first rental property. When is the best time to get preapproved for a mortgage?

 Now works. When the lender asks for paystubs, provide your current paystubs AND the offer letter. 

I would start talking with banks and build that relationship. From my experience, its pretty easy for a banker to give you a pre-approval letter. The banker will give you a pre-approval letter now based on your income, and when you start the new job just give the banker a pay stub and if it effects the pre-approved amount then the banker will change the letter. 

I'd def reach out to the banker(s) because depending on the new job you might have to wait x amount of time. Usually this isn't a big issue if it's in the same career field and you have a documented work history... 

As @Chris Mason  mentioned, get approved now. Here is the Fannie Mae guideline in regards to offer letters, and how they can be used for qualification purposes.