Getting a Mortgage in Principle: what you need to know

What is a Mortgage in Principle? 

A Mortgage in Principle – also known as an Agreement in Principle, Decision in Principle or Mortgage Promise – is a personalised statement from a lender showing how much they may be willing to lend you, based on the information you’ve shared so far. 

It’s not a legal requirement, but many estate agents will ask to see one. Having a MIP can help you understand the price range you can search within and view properties with more confidence. You’re not committing to anything at this stage. 

How long does a Mortgage in Principle last? 

Most MIPs are valid for up to 90 days, although this can vary by lender. If your MIP expires, you’ll need to apply again. 

How long does it take to get a Mortgage in Principle? 

For most people, completing an online MIP application takes around 10 minutes. Once submitted, the lender’s decision is usually generated within seconds. 

Get a Mortgage in Principle

Mortgage in Principle vs a full mortgage offer 

A MIP is a step towards a mortgage offer 

When you’ve found a property and had an offer accepted, you’ll still need to make a full mortgage application. If you already have a valid MIP, the lender or a broker may be able to reuse some of the information you’ve provided, although they’ll need to check it’s still accurate. 

A MIP is not a guarantee 

A Mortgage in Principle shows how much a specific lender may be willing to lend, based on the information available at the time. It doesn’t guarantee you’ll receive a mortgage offer. 

If new information comes to light during the full application – or if your circumstances change – the lender’s decision, the amount they’ll lend, the interest rate or the mortgage term could all be affected. 

Why get a Mortgage in Principle? 

Although you don’t need a MIP to view properties, it’s a very useful document to have and is usually part of the mortgage process once an offer is accepted. 

Reassurance about affordability 

A MIP gives you a clearer idea of what you could afford and how much a lender may be willing to lend. As long as there’s no major change in your circumstances or wider economic factors, it can provide reassurance ahead of a full mortgage application. 

Credibility with estate agents and sellers 

Having a MIP shows that you’re in a position to proceed and could afford the property you’re interested in. This can help you secure viewings more quickly, particularly in competitive markets, and reassures sellers that you’re a serious buyer. 

Confidence earlier in your search 

With a MIP in place, you can focus on properties within your likely budget and make decisions with greater confidence. 

A Mortgage in Principle can be useful whether you’re a first‑time buyer or you’ve owned a home before, and whether you’re buying on your own, or with someone else.

It gives you a clearer idea of what you could afford, and shows estate agents and sellers that you’re serious about moving forward, and in fact, just under three quarters of people we spoke to* (74%) told us they wanted to know what their budget would be before they start searching for their next home. While it’s not a guarantee of a mortgage, having a MIP in place can make searching for and offering on a home feel far more straightforward, and helps you go into the process with confidence.

*Rightmove’s research panel – Living Room, survey of 986 users, including homeowners with a mortgage and future first-time buyers, June 2025 

Get a Mortgage in Principle

Will getting a MIP affect my credit score? 

As part of your application, the lender will run a credit check. 

Most lenders use a soft credit check for a Mortgage in Principle, which isn’t recorded on your credit file. Some may use a hard check, which does leave a footprint and could affect your credit score if you apply several times in a short period. 

When you submit a full mortgage application, any previous soft checks usually become hard checks. It’s always worth checking which approach your chosen lender uses. 

Is the process different in Scotland? 

The home‑buying process in Scotland is different, and while a MIP still isn’t a legal requirement, it’s often viewed as a stronger indication of your intent to buy. 

How to get a Mortgage in Principle 

You can apply for a MIP directly with a lender or through a mortgage broker. You can also apply online on Rightmove. 

What information will you need? 

You’ll usually be asked for: 

• basic personal details 

• information about your income and outgoings 

• details of existing credit commitments 

You may not need to provide documents at this stage, but it’s helpful to have things like payslips or bank statements to hand, so the information you submit is accurate and consistent. 

Does a Mortgage in Principle cost anything? 

An online MIP is usually free. Some mortgage brokers may charge a fee to use their services, so it’s best to check before applying. 

What could affect a full mortgage application? 

Because a MIP isn’t a guarantee, a lender’s final decision can be affected by several factors, such as: 

Changes to your circumstances 

Changes to your income, spending, employment, family situation or financial commitments could affect how much you can borrow – or whether a lender is willing to lend at all. 

Information not matching supporting documents 

If the information provided in your MIP doesn’t align with documents checked later, the lender may change their decision, adjust the loan amount or decline the application. 

The property itself 

Even if your circumstances haven’t changed, lenders have their own criteria about which properties they’ll lend on. This could include restrictions on new‑build developments, unusual construction types, short leases, or properties with higher risks such as flooding or subsidence. 

Reapplying after your MIP expires 

If your MIP expires and you apply again, you may receive a different result – even if nothing has changed – due to updates in the lender’s policies or risk criteria. 

FAQs

• Do I need a Mortgage in Principle before attending a house viewing?

  No. You don’t need a Mortgage in Principle to book viewings. However, having one can help you understand your budget and may make estate agents more confident that you’re in a position to proceed. 

• Can I make an offer on a property without a Mortgage in Principle?

  Yes, you can. But many estate agents and sellers prefer buyers to have a MIP in place, as it shows you’re likely to be able to secure a mortgage if your offer is accepted. 

• What happens if my circumstances change after I get a MIP?

  If your income, spending, job, or personal situation changes, this could affect the outcome of your full mortgage application. It’s important to let your lender or broker know about any changes as early as possible. 

• Does a Mortgage in Principle lock me into a lender?

  No. A Mortgage in Principle doesn’t commit you to taking out a mortgage with that lender. You’re free to compare options or use a different lender when you apply for a full mortgage. 

• Can I use the same Mortgage in Principle for different properties?

  Yes. As long as your MIP is still valid, you can use it while viewing and offering on different properties. You don’t need a new one for every home you’re interested in. 

• How long does getting a Mortgage in Principle take?

  For most applicants, it takes about 10 minutes to fill in the online application. Once submitted, the decision from the lender in generated within seconds. 

• What should I do if my Mortgage in Principle expires?

  If your MIP expires, you’ll need to apply for a new one. Even if your circumstances haven’t changed, the result could be different due to updates to a lender’s criteria or policies. 

Please note: Rightmove is not authorised to give financial advice; the information and opinions provided in these articles are not intended to be financial advice and should not be relied upon when making financial decisions. Please seek advice from a regulated mortgage adviser.