An Agreement in Principle (AIP), also called a Decision in Principle is a handy piece of paper (or PDF) that shows how much a lender *might* let you borrow.

It’s not a guarantee, but it gives estate agents and sellers the warm fuzzy feeling that you’re serious. You haven’t just wandered in off the street , you’ve had your finances checked (lightly) and you’re ready to move.

How long does it last?

Most AIPs are valid for 2–3 months. That gives you a decent window to view homes, put in offers, and start getting your docs together.

If yours runs out before you find your dream place…. no stress. You can usually get it renewed (as long as nothing major has changed in your finances).

Do I need an AIP before viewing homes?

Strictly speaking, no but it helps. A lot.

Estate agents love to see an AIP before booking viewings or accepting offers. It tells them you’re not just ‘window shopping’, you’re mortgage-ready. And that gives you an edge in competitive markets.

Next steps:

From AIP to Full Mortgage Offer

Once your offer on a home is accepted, things get real.

Here’s what happens next:

  • You apply for the actual mortgage
  • The lender does a full affordability and credit check
  • A surveyor values the property
  • If all goes smoothly, you get a formal mortgage offer

That’s your golden ticket to the next stage: exchange and completion.

At this point, the AIP steps aside and the real mortgage offer takes over.

Common pitfalls to avoid

Thinking an AIP = a mortgage: It doesn’t. It’s a ‘maybe’, not a ‘yes’.

Rushing into a home you’re not sure about: Just because you’ve got the AIP doesn’t mean you need to buy right now.

Letting your financial situation change: Big spending sprees, job changes, or new loans between your AIP and full mortgage application could throw things off.

Top tip? Keep everything steady and speak to a broker before doing anything major. We’ve seen it all, and we’re here to help.

In a nutshell

An Agreement in Principle is your starter key, it unlocks viewings, confidence, and credibility. But it’s just the beginning.

From here, it’s about finding the right place, locking in the right mortgage, and getting those keys in your hand.

And if you’re feeling a bit lost? Don’t worry, Habito can guide you every step of the way.