Published: 3 November 2025
Getting a Mortgage in Principle: Explained
A mortgage in principle is the first step in getting a mortgage. If you’re a first time buyer setting sail for the first time, it’s a really useful document to have. And if you’re a home-mover, it’ll also stand you in good stead. Let’s look at the mortgage in principle in more detail.
What is a mortgage in principle?
Do you know how much you’re going to be able to borrow to buy a home? It’s a crucial question, and knowing the answer helps put you on the right property path.
Before you start looking for a home, a mortgage in principle is a statement from a lender that gives you an idea of how much they might be willing to lend you to buy a home. A mortgage in principle is also sometimes called a ‘decision in principle’, ‘agreement in principle’ or an ‘approval in principle’.
It’s based on information you give to your lender about your financial circumstances and, while it’s not final or legally-binding, a mortgage in principle is a handy document to have. That’s because it:
• Gives you a realistic idea of how much you might be able to borrow, so you can focus your property search and look for homes you can afford
• Sets you up as a serious buyer to sellers and estate agents – especially helpful when the property market is busy and there is competition for homes
It’s important to remember that a mortgage in principle is only a rough idea of what a lender might be able to lend you.
How to get a mortgage in principle?
With a lot of lenders you can apply for a mortgage in principle online and they usually have dedicated mortgage in principle sections on their websites. You could also get one over the phone, in a bank or building society branch or through a mortgage broker.
You’ll need to provide some information about your financial situation – your lender will then consider this information against its lending and affordability criteria to outline how much they may be able to lend to you.
This information usually includes:
• How much you earn and details of your work (for example, if you’re employed or self-employed)
• Details of your current financial outgoings (like regular payments, spending commitments and credit commitments)
• Whether you have an existing mortgage
• Whether you have any financial dependents
It’s important to remember that if your financial circumstances change, the amount a lender might be able to lend you may change too.
How long does a mortgage in principle last?
They are usually valid for a set period of time – often from 30 to 90 days but this may vary depending upon the lender. Check with them. A mortgage in principle from Leeds Building Society is valid for 90 days . The good thing is if your mortgage in principle does run out, it’s quick and easy to get another one.
How reliable is a mortgage in principle?
A mortgage in principle is a reliable indication of what you might be able to borrow based on the financial details you’ve provided - but it’s not a guarantee or a promise.
That’s why a good way of thinking about a mortgage in principle is that it’s only as reliable as the information you have provided – so it’s crucial you make sure this is as accurate and up to date as possible.
Does a mortgage in principle affect credit score?
Usually, no, because while most lenders will run a credit check when you apply for a mortgage in principle, they’ll typically do this using a ‘soft’ check. This doesn’t leave a footprint on your credit file. Some lenders may run a ‘hard’ check, which does leave a mark and could affect your score. If you’re worried about this, check with your lender.
If you’re a first time buyer and would like more information on credit scores, including how they work, what they mean and how they can be improved, read our guide to credit scores .
How long does a mortgage in principle take?
A mortgage in principle applied for online is pretty quick – expect it to take about 15 minutes to apply for one. Add in some extra time to get any necessary paperwork together beforehand (like wage slips and details of financial outgoings). A mortgage in principle arranged over the phone, through a mortgage broker or in a bank or building society branch could take a little longer.
Can you view a house without a mortgage in principle?
Yes, you can – a mortgage in principle isn’t a requirement when you go and look at a house you’re interested in. However, going armed to a viewing with a mortgage in principle can give you an advantage, as it shows sellers and estate agents that you’re credible. It could also put you in a stronger position if you end up negotiating, and is a good idea when the housing market is busy and there’s strong competition for properties.
Found out what you need to know about a mortgage in principle? Good luck as you take the next exciting steps toward finding and buying your new home!
