Key facts
- Primary keyword: mortgage in principle - independent editorial guide, no commission
- Primary sources: FCA, gov.uk, Money and Pensions Service
- Last reviewed June 2026 by Chandraketu Tripathi, Finance Editor
What Is a Mortgage in Principle?
A mortgage in principle is a lender's written indication of how much it is prepared to lend based on an initial assessment of the borrower's finances, before a property is found. Also called an agreement in principle (AIP) or decision in principle (DIP), a mortgage in principle is not a formal mortgage offer and is not legally binding.
Lenders conduct an initial affordability assessment and credit check when issuing a mortgage in principle. The level of check varies - some conduct a hard search visible on the credit file; others conduct a soft search that does not affect the score. Borrowers should ask which type applies before requesting a mortgage in principle.
A mortgage in principle is typically valid for 60 to 90 days. If circumstances change during that period - new debt, job change, credit events - the lender may reassess when the full application is submitted, even if the mortgage in principle was issued without issue.
Why Estate Agents Ask for a Mortgage in Principle
Many estate agents require a mortgage in principle before accepting an offer. This is not legally mandated but is common practice, particularly in competitive markets. A mortgage in principle signals that the buyer has completed initial financial checks and reduces the risk of a late-stage collapse.
Vendors and their agents prefer buyers who hold a mortgage in principle because it indicates the purchase can be financed at approximately the stated price. In competitive markets where multiple buyers make offers simultaneously, a mortgage in principle can strengthen a buyer's position.
However, a mortgage in principle does not guarantee final approval. The full application requires income document verification, a detailed credit assessment, and a property valuation. Any of these stages can produce a different outcome to the indicative mortgage in principle.
How to Get a Mortgage in Principle
A mortgage in principle can be obtained directly from a lender online or by telephone, or through a mortgage broker. Most major lenders have online tools that generate a mortgage in principle decision within minutes based on basic income and outgoings.
A whole-of-market broker can assess which lenders are most likely to convert a mortgage in principle into a full approval for a specific borrower profile. A single targeted application is preferable to multiple applications, particularly where hard searches are involved.
Information required for a mortgage in principle typically includes: full name and date of birth; address history for three years; employment status and income; existing financial commitments; estimated purchase price; and deposit amount. No property details are needed at this stage of the mortgage in principle process.
What a Mortgage in Principle Does Not Guarantee
A mortgage in principle is an indication, not a commitment. Several factors can result in a different outcome at full application: the property valuation may come in below the purchase price, changing the loan-to-value ratio; income documents may differ from the figures used for the mortgage in principle; credit history issues may emerge under closer assessment.
Borrowers should not make non-refundable commitments - survey fees, exchange of contracts, giving notice on a rental property - solely on the basis of a mortgage in principle. The formal mortgage offer is the binding document.
The mortgage in principle validity period of 60 to 90 days also means that if property search takes longer, a new application is required. Changes in interest rates or lender criteria during this period may affect the outcome of the renewed mortgage in principle.
Hard vs Soft Credit Searches for a Mortgage in Principle
The distinction between hard and soft searches is critical when applying for a mortgage in principle. A hard search records an enquiry on the credit file visible to all future lenders. Multiple hard searches in a short period reduce the credit score and signal potential financial instability.
A soft search retrieves credit information without appearing on the credit file. It has no impact on the credit score and is invisible to other lenders. Borrowers comparing mortgage in principle offers from multiple lenders should confirm whether each application involves a hard or soft search.
Using a broker to identify the most appropriate lender and making a single mortgage in principle application minimises search exposure and protects the credit profile during the property search period.
After the Mortgage in Principle: Next Steps
Once a mortgage in principle is in place, the borrower is positioned to make credible offers. Estate agents should be informed the mortgage in principle is in place when submitting an offer - it strengthens the position versus buyers who have not taken this step.
If an offer is accepted, submit the full mortgage application with the chosen lender before the mortgage in principle expires. A full application within the validity window avoids a new credit search and ensures the indicative rate from the mortgage in principle remains available.
Between receiving the mortgage in principle and the formal offer, avoid taking on new credit - car finance, credit cards, loans. Any new commitment changes the debt profile assessed in the mortgage in principle and may alter the outcome of the full application. Stability of income, outgoings and credit between mortgage in principle and formal offer produces the smoothest transition. The mortgage in principle process is designed to be straightforward and low-risk for the borrower. Taking the time to obtain a mortgage in principle before beginning a serious property search puts the buyer in the strongest possible position when making offers and demonstrates financial preparedness to vendors.
Disclaimer: This guide is for informational purposes only and does not constitute financial advice. Mortgage products, eligibility criteria and regulations change frequently. Consult an FCA-authorised mortgage adviser before making any decision. Kael Tripton Ltd is not authorised or regulated by the Financial Conduct Authority.
Frequently Asked Questions
What is a mortgage in principle and how does it work?
A mortgage in principle is an initial written indication from a lender of how much it will lend, based on a basic financial assessment. It is not a formal offer or guarantee of a mortgage. It is used to show estate agents and vendors that a buyer has completed initial financial checks.
Does a mortgage in principle affect my credit score?
It depends on whether the lender conducts a hard or soft credit search. A soft search has no impact. A hard search reduces the score slightly and is visible to other lenders. Always ask which applies before requesting a mortgage in principle.
How long does a mortgage in principle last?
A mortgage in principle typically lasts 60 to 90 days before it expires. If circumstances change during that period, the lender may reassess when the full application is submitted.
Do I need a mortgage in principle before making an offer?
There is no legal requirement, but most estate agents ask for one. A mortgage in principle makes an offer more credible to the vendor and is particularly important in competitive markets.
How quickly can I get a mortgage in principle?
Most lenders provide a mortgage in principle decision within minutes via online tools. A broker may take slightly longer if they are comparing options across multiple lenders to identify the most suitable.
Sources
Last reviewed June 2026 by Chandraketu Tripathi, Finance Editor, Kaeltripton.com
