Buyers ask it as though one word is the good one and the other is the weak one, and they want to know which they have. The Consumer Financial Protection Bureau's answer is that lenders do not use the two words the same way. So the word is the wrong thing to look at.
The short answer
Either letter says a lender is willing to lend up to an amount, based on assumptions. Neither one is a guaranteed loan offer. What decides how much the letter is worth is what the lender verified before writing it: your income, your assets and your credit, or only what you told them.
Why the words blur
Some lenders call a letter a prequalification when it rests on information you reported and nobody has checked yet, and reserve preapproval for a letter written after they have seen the documents. Other lenders draw the line differently. The CFPB says plainly not to worry about which word a lender uses. Ask what was checked instead.
What to ask the lender
- Did you pull my credit, or is this based on what I told you
- Have you seen my pay records and my bank statements, or only heard the numbers
- What would have to be true about the house for this letter to hold
- What is still left to review, and what could change the amount
- How long is this letter good for
A lender who answers those five questions in writing has given you something useful. A lender who cannot answer them has given you a letterhead.
What a seller reads in it
A seller comparing two offers is comparing risk, not only price. The letter is the seller's only window into whether your financing will survive underwriting. A letter from a lender that has reviewed your documents, with a name and a phone number on it, reads as a buyer who has done the work. A form letter produced in ten minutes reads as a question mark, and a question mark loses to a slightly lower offer with a better letter more often than buyers expect.
Why earlier is better
The CFPB makes a point worth repeating: getting preapproved before you shop seriously gives you time to find a problem on your credit report and fix it. Found in the spring, a reporting error is a letter to the bureau. Found three days into a purchase contract, it is a deadline. For anyone relocating, it also means the budget is settled before the house-hunting trip is booked, not during it.
The uncomfortable part
The letter is not the loan. Buyers change jobs, finance a car or move money between accounts after the letter is written, and every one of those can change what the lender will do. The approval that matters is the one that survives to closing, and the safest month to make no financial changes at all is the month you are under contract.
The part I will not answer
How much you will qualify for, at what rate, and on which loan program belongs to your lender. Whether a larger payment is sensible for your household belongs to you, and where it touches taxes or retirement money, to your CPA or financial adviser. I will tell you what a letter looks like to a seller in this market. I will not tell you what you can afford.
The affordability page is a place to start the arithmetic, and the buyers page sets out where the letter fits in the sequence.
Source: Consumer Financial Protection Bureau, "What's the difference between a prequalification letter and a preapproval letter?" Read at source, September 2026.
This note is general. It is not lending or financial advice, and what you qualify for depends on a lender's review of your own finances.