Updated April 2026 · Kael Tripton · Finance Guide

Important: This guide is for information only and does not constitute financial advice. Mortgage rates change daily. Always get personalised advice from an FCA-regulated whole-of-market mortgage broker. Your home may be repossessed if you do not keep up repayments on your mortgage.

What Is a Mortgage in Principle and How Do You Get One?

A mortgage in principle (MIP) - also called an agreement in principle (AIP) or decision in principle (DIP) - is a written estimate from a lender of how much they may be willing to lend you based on a preliminary assessment of your finances. As MoneyHelper describes it: a written estimate of how much a mortgage provider is willing to lend you based on a quick check of your income and in some cases your credit file. It is not a guaranteed mortgage offer, but it shows estate agents and sellers you are a serious buyer.

What a Mortgage in Principle Tells You

An MIP gives you: a clear indication of your approximate borrowing limit based on your income and outgoings; reassurance for estate agents that you are a credible buyer; a focus for your property search within your realistic budget; and a head start on the formal mortgage application once you have had an offer accepted.

It is not a guarantee. When you proceed to a full mortgage application, the lender carries out much more detailed affordability checks, a credit assessment, and a valuation of the specific property. The full mortgage approval process typically takes 2 to 6 weeks from application to offer (HSBC, 2026).

How Long Does a Mortgage in Principle Last?

Most UK lenders set a validity period of 30 to 90 days for a mortgage in principle. Specific lender terms in 2026:

If your MIP expires before you find a property, you can reapply. Most lenders allow renewal without a hard credit check, though they will reassess your circumstances.

Soft vs Hard Credit Check

Most UK lenders use a soft credit check for the MIP stage in 2026. A soft check reviews your credit file but leaves no footprint visible to other lenders - it does not affect your credit score. A hard check creates a visible footprint. Multiple hard checks in a short period can signal financial difficulty to lenders and may affect your mortgage application. Always ask which type of check a lender uses before applying.

How to Get a Mortgage in Principle

Getting an MIP is straightforward and quick. The online process with most major lenders takes around 10 to 15 minutes, and some fully automated systems provide a decision in under 15 minutes. You will typically need to provide:

• Your name, date of birth, and address history (usually 3 years)
• Employment status and income details
• Monthly outgoings including existing loans and credit cards
• The deposit amount and source
• National Insurance number (for credit check)

Once submitted, most lenders provide an instant online decision and a certificate you can show to estate agents confirming your approximate borrowing limit.

Frequently Asked Questions

Do I need an MIP before viewing properties?

Not legally - estate agents cannot refuse viewings because you lack an MIP. However, in competitive markets many agents prioritise buyers with an MIP. Having one ready before you start active searching is best practice.

Will getting an MIP affect my credit score?

If the lender uses a soft credit check (the majority do in 2026), no - soft checks are invisible to other lenders and do not affect your credit score. If a lender uses a hard check, it will appear on your credit file. Always confirm which type is used before applying.

Can I get an MIP with bad credit?

You may still be able to get an MIP with adverse credit history, depending on the nature and age of the issue. Some lenders specialise in adverse credit mortgages. A declined MIP does not close all options - approach a specialist adverse credit mortgage broker before concluding you cannot get a mortgage.

How much can I borrow for a mortgage?

Most lenders in 2026 offer between 4 and 4.5 times your annual gross income, subject to affordability checks. Some lenders offer up to 5 or 5.5 times income for specific professions or first-time buyers with strong profiles. Use a mortgage calculator for an initial estimate, then get an MIP for a personalised figure.

Is an MIP the same as a mortgage offer?

No. An MIP is a preliminary indication - not binding on the lender. A mortgage offer is a formal legally binding commitment issued after the full application has been assessed and approved. You can only exchange contracts on a property purchase once you have a formal mortgage offer.

Conclusion

A mortgage in principle is the essential first step for any UK home buyer in 2026. Most major lenders offer online MIPs taking 10 to 15 minutes using a soft credit check that does not affect your credit score. Validity is typically 60 to 90 days. Barclays and Nationwide offer 90 days; Santander offers 60 days. For the most comprehensive MIP across multiple lenders, use a fee-free whole-of-market mortgage broker. Visit MoneyHelper for impartial mortgage guidance.

Last updated: April 2026. Rate data sourced from HomeOwners Alliance, Rightmove, and lender published rates April 2026. Rates change daily - always verify before applying. For free impartial guidance visit MoneyHelper.