What Is a Decision in Principle and Do You Need One Before House Hunting in the UK?

What Is a Decision in Principle?

A Decision in Principle (DIP) — also called an Agreement in Principle (AIP) or mortgage in principle — is a written statement from a lender confirming how much they would potentially be willing to lend you, based on some initial checks. It is not a full mortgage offer, and it does not guarantee you will be approved. Think of it as a confident first step rather than a done deal.

Lenders typically look at your income, your outgoings, and run either a soft or hard credit check to produce this figure. The whole process usually takes less than 30 minutes online.

Do You Actually Need One Before House Hunting?

Strictly speaking, no — there is no legal requirement to have a Decision in Principle before you start viewing properties. However, in practice, most estate agents will ask to see one before they take your offer seriously, and some will refuse to submit an offer to the seller without it.

If you are already feeling stressed about money or worried whether a lender will even consider you, getting a DIP early can actually bring real peace of mind. It tells you what budget you are working within, so you are not falling in love with a home you cannot afford.

Tip: Getting a DIP before you start viewing is strongly recommended. It strengthens your position as a buyer and shows sellers you are serious.

How Do You Get a Decision in Principle?

You can apply for a DIP:

• Directly with a lender (bank or building society) — online, by phone, or in branch
• Through a mortgage broker — a broker can compare multiple lenders and find the best fit for your circumstances, which is especially helpful if your credit history is not perfect

You will typically need to provide:

1. Proof of identity (passport or driving licence)
2. Your address history for the last three years
3. Details of your income (employed salary or self-employed earnings)
4. Information about any existing debts or financial commitments

The lender will then carry out a credit check. Ask whether this is a soft or hard search — a soft search does not leave a mark on your credit file, whereas a hard search does. Multiple hard searches in a short space of time can temporarily lower your credit score, which matters if you are already worried about your financial record.

How Long Does a Decision in Principle Last?

Most DIPs are valid for 60 to 90 days. If your house hunt takes longer than that — which is not uncommon, especially in a slow market — you can usually renew it. Just be aware that if you renew with a hard credit check, it will show on your file again.

What If You Have Bad Credit or Financial Difficulties?

This is one of the most common worries people bring to this question, and it is completely understandable. If you have missed payments, have a County Court Judgement (CCJ), or have been in debt management, you may be concerned a DIP will come back declined.

Here is what you should know:

• Some specialist lenders cater specifically to people with adverse credit history. A good mortgage broker who works with the whole of the market can point you towards these lenders.
• A soft search DIP means a decline will not harm your credit score, so it is worth asking for this option first.
• Being declined for a DIP does not mean you cannot ever get a mortgage — it may simply mean this particular lender’s criteria do not suit your circumstances right now.
• MoneyHelper (the free, impartial service backed by the government at moneyhelper.org.uk) offers guidance on improving your credit profile before applying.

Remember: A DIP is not a final decision. Many people who struggle to get a DIP from a high street bank find success with a specialist lender or after a short period of credit rebuilding.

Does a Decision in Principle Guarantee a Mortgage?

No. This is really important to understand. A DIP is based on limited information. When you submit a full mortgage application, the lender will carry out a much more thorough review, including:

• Verified payslips and bank statements
• A full credit check
• A property valuation (to ensure the home is worth what you are paying)

It is possible to be declined at full application stage even after receiving a DIP. This can happen if your circumstances change, if the property valuation comes in lower than expected, or if the lender finds something during full underwriting that was not apparent at the DIP stage.

Does a DIP Affect Your Credit Score?

Only if the lender runs a hard credit search. Always ask upfront which type of search they will perform. If you are shopping around between multiple lenders, try to use soft searches where possible to protect your credit score during the early stages.

Are There Any Other Schemes That Might Help?

If affordability is a stretch, it is worth exploring:

• Shared Ownership — buy a share of a property (typically between 10% and 75%) and pay rent on the rest, available through housing associations
• First Homes scheme — offers discounts of at least 30% on new-build homes for first-time buyers in England
• Lifetime ISA (LISA) — save up to £4,000 per year and receive a 25% government bonus towards your first home (for properties up to £450,000)

A mortgage broker or the MoneyHelper website can help you understand which schemes you might qualify for.

Quick Summary

Getting a Decision in Principle is a sensible early step in your home-buying journey — particularly if you are navigating financial difficulties and want to understand your options clearly before committing time and emotion to properties that may be out of reach. You deserve to house hunt with confidence.

This article is for informational purposes only and does not constitute regulated financial advice. Mortgage products and lending criteria change regularly. Always consult a qualified, FCA-authorised mortgage adviser before making financial decisions.