IRS private letter ruling PLR-157111-06.  

I would start by ensuring you have your forms, form letters, website, and everything ready to hit the ground running.

Most builders require you to provide a Pre-approval letter or Loan commitment from the bank.

If they give you a proof of funds letter without a full application and credit review burn it.

Would a letter from the neighbor suffice? 

@Taylor CookBe sure to get an estoppel letter signed by the tenants and seller stating the current amount of the security deposit and any other pertinent facts not recorded in the lease.

I typically recommend beginning with a prequalification letter so you can have a solid understanding of your purchase power in the U.S., which will help steer you into the right markets/areas for investing.

Establish relationships with brokers specializing in multi-family properties, send letters to property owners, and use online platforms like LoopNet, Crexi, and CoStar.

In the future perhaps I should get a unique address number to avoid confusion.I will try and go to the post office and show them the letter but not sure if they will help me.

Neighbor letter campaign (but there are no nearby towns)5.