An Agreement in Principle (AIP), also called a Decision in Principle or Mortgage in Principle, is a lender's provisional indication of how much it would lend you, based on a soft credit check. It is not a guaranteed mortgage offer, usually lasts 30 to 90 days, and is often free to get online in minutes.
Other names - Decision in Principle (DIP) or Mortgage in Principle (MIP) - the same thing
What it is - A lender's provisional estimate of how much it is willing to lend you
Credit check - Usually a soft check that leaves no mark on your file; some lenders use a hard check
How long it lasts - Typically 30 to 90 days, after which it can usually be renewed
Plus 3 more in the full guide

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