TL;DR: UK mortgage lenders do not use a single national credit score. Each lender runs its own credit-scoring model against credit history data supplied by Experian, Equifax and TransUnion (the three UK credit reference agencies). The same applicant can be approved by one lender and declined by another based on different scorecards. Most mainstream lenders look at the actual history (defaults, county court judgments, missed payments, credit utilisation, length of credit history, electoral roll, recent applications) rather than a single number. There is no minimum number that "passes". A clean recent credit history (no missed payments in the last 12 to 24 months, no defaults in the last 6 years, modest credit utilisation, presence on the electoral roll) is the practical target. Specialist lenders accept borrowers with adverse credit on higher rates.
Last reviewed May 2026
UK borrowers often ask "what credit score do I need for a mortgage?" expecting a single threshold number. The honest answer is that there is no such single number. The credit scores quoted by Experian, Equifax and TransUnion to consumers (each on its own scale) are not the scores mortgage lenders use; each lender runs its own internal credit-scoring model against the same underlying credit history data. The score that matters is the one the lender produces, not the one the consumer sees on a credit reference agency app.
This guide explains how UK mortgage credit assessment actually works, what lenders look at in the credit history, the relationship between consumer credit scores and lender decisions, the specialist lender market for adverse credit, and the practical steps to improve credit history before applying.
The three UK credit reference agencies
Three credit reference agencies (CRAs) hold UK consumer credit history data: Experian, Equifax and TransUnion. Each agency holds essentially the same factual data (the agencies receive data from lenders, public records and the electoral register), but the layout, presentation and the consumer-facing "score" each agency produces are different. A consumer can have a "good" score from one agency and a "fair" score from another on the same underlying history.
The consumer-facing scores (Experian's score out of 999, Equifax's score out of 1,000, TransUnion's score out of 710) are produced by the CRA's own algorithm and are intended for the consumer's own use. They are not the score the mortgage lender uses. Lenders pull the underlying credit history data and apply their own scoring model.
UK consumers have the legal right to access their credit report at each CRA under data protection law. Each CRA must provide a "statutory credit report" free of charge, and the consumer-facing scores are typically available in apps and online platforms operated by the agencies and by third parties (such as ClearScore for Equifax data and Credit Karma for TransUnion data).
What lenders actually look at
Mortgage lenders typically look at six broad categories of data in the credit history. The first is defaults and serious adverse events: county court judgments (CCJs), individual voluntary arrangements (IVAs), bankruptcies, debt relief orders, and any default markers on credit accounts. These stay on the credit file for six years and are weighted heavily.
The second is recent missed payments: late payments on credit cards, personal loans, car finance, store cards, mobile contracts and other credit accounts. Missed payments in the last 12 to 24 months are particularly significant; older missed payments matter less. The pattern of missed payments (one isolated late payment versus a long run of arrears) affects the weighting.
The third is credit utilisation: the proportion of available credit limits in use. A consumer using 90 percent of their credit card limits looks higher risk than the same consumer using 20 percent, even if both are paying on time. The fourth is the length of credit history: lenders prefer applicants with several years of well-managed credit history over applicants who have only recently started using credit.
The fifth is recent credit applications: multiple recent applications can suggest financial pressure or a "rate shopping" pattern that lenders sometimes view negatively. Soft searches (such as those done for an agreement in principle) do not affect the score; hard searches do. The sixth is the electoral roll presence at the applicant's address, which helps confirm identity and stability.
The relationship between consumer scores and lender decisions
A high consumer score at Experian, Equifax or TransUnion is a useful proxy for the underlying credit history being in good shape, but it is not a guarantee of mortgage approval. Lenders apply their own affordability assessment alongside the credit check; an applicant with a perfect credit history but inadequate income for the requested loan will still be declined. Conversely, an applicant with some adverse history can still be approved by a lender whose scorecard tolerates the specific markers.
Lender scorecards are typically not disclosed publicly; the specific weightings are commercially sensitive. Mortgage brokers build up working knowledge of which lenders are tolerant of which issues. A broker who knows that Lender X tolerates a defaulted mobile phone bill from three years ago, while Lender Y does not, can place the case with the lender most likely to approve.
The score itself does not appear in the mortgage offer; the consumer sees only the outcome (approved or declined) and, if approved, the rate and product offered. If declined, the lender typically does not state the specific reason in detail, but is required under data protection rules to indicate the principal reason category on request.
Common credit history issues and how lenders treat them
A few specific issues come up repeatedly. A defaulted credit card or loan account stays on the credit file for six years from the date of default. Most mainstream lenders are unable to approve borrowers with defaults registered in the last 24 to 36 months; specialist lenders can accept borrowers with older defaults at higher rates.
A county court judgment (CCJ) stays on the public register and on the credit file for six years from the date of the judgment, unless settled in full within one month (in which case it can be removed). An unsatisfied CCJ is more serious than a satisfied one. Mainstream lenders normally require any CCJs to be at least 3 years old and satisfied; specialist lenders can accept more recent CCJs at higher rates.
An Individual Voluntary Arrangement (IVA) is a formal debt arrangement that stays on the credit file for six years from the date of the IVA, even after the IVA has been completed. Bankruptcies stay on the file for six years from the date of the bankruptcy order. Both are typically declined by mainstream lenders; specialist lenders can accept borrowers with completed IVAs or discharged bankruptcies at significantly higher rates.
Missed payments in the last 12 months are weighted heavily. A single missed mortgage payment in the last 12 months can cause mainstream lender decline; multiple missed payments across several accounts are more problematic. The pattern matters: a one-off missed payment due to a known event (a forgotten direct debit, a bank error) can sometimes be explained and weighed differently from a pattern of arrears.
Specialist lender market for adverse credit
A meaningful share of the UK mortgage market specialises in adverse credit cases. These lenders, sometimes called specialist or sub-prime lenders, accept borrowers with defaults, CCJs, IVAs, bankruptcies and missed payments that mainstream lenders decline. The rates are higher than mainstream rates, the loan-to-value caps are often lower, and the products are designed to be refinanced once the adverse history is older.
Typical specialist lender criteria categorise borrowers by the severity and recency of their adverse credit. Tier 1 might allow defaults over 36 months old, no CCJs, no missed payments in the last 12 months. Tier 2 might allow defaults over 24 months, satisfied CCJs over 36 months, no missed payments in the last 6 months. Tier 3 and below accept more recent issues at progressively higher rates.
The advice from a specialist mortgage broker is particularly valuable in adverse credit cases. The broker maps the specific credit history to the lenders most likely to approve, manages the application to maximise the chance of acceptance, and plans the refinancing strategy once the adverse markers age off the file.
Practical steps to improve credit before applying
Six months to two years before a planned mortgage application, several steps can materially improve the credit position. The first is to check the credit reports at all three CRAs (Experian, Equifax and TransUnion) and dispute any inaccuracies. CRAs have a legal duty to correct factually wrong data.
The second is to register on the electoral roll at the current address. The third is to settle or satisfy any outstanding defaults or CCJs, which converts them from unsatisfied to satisfied on the file. The fourth is to reduce credit utilisation, ideally to below 30 percent of available limits. The fifth is to avoid new credit applications in the six months before the mortgage application, except where unavoidable.
The sixth is to keep paying every account on time for at least 12 months. The pattern of recent good payment is a strong signal to lenders, even alongside older negative markers. The combination of fixing the inaccuracies, registering on the electoral roll, satisfying defaults, reducing utilisation and maintaining clean recent payment history can materially shift the lender outcome over a 12 to 24 month preparation window.
How we verified this
This article reflects the FCA's Mortgage Conduct of Business Sourcebook (MCOB) for the regulatory framework, the Information Commissioner's Office guidance on credit reference agencies and consumer rights, the legal framework for default registration and CCJ retention under the Limitation Act 1980 and credit reference agency conventions, and the published principles for the Standing Committee on Reciprocity that govern how lenders share credit data through the CRAs. Specific lender criteria and current rates change frequently and should be checked through a mortgage broker or directly with each lender.
Disclaimer: This article is general information about UK mortgage credit assessment. It is not financial advice. Each lender applies its own scoring model and the assessment depends on the full picture of credit history, affordability and the property. Anyone with credit history concerns should take advice from an FCA-authorised mortgage broker who covers the specialist lender market.
Frequently asked questions
What credit score do I need for a UK mortgage?
There is no single national credit score that lenders use to approve or decline mortgages. Each lender runs its own internal scoring model against credit history data from Experian, Equifax and TransUnion. The consumer-facing scores from those agencies are not the scores lenders use. A clean recent history (no missed payments in 12 to 24 months, no defaults in 6 years, modest credit utilisation, electoral roll presence) is the practical target.
Will a low credit score stop me getting a mortgage?
A low consumer-facing credit score suggests issues in the credit history that mainstream lenders may decline. Specialist lenders accept borrowers with adverse credit (defaults, CCJs, IVAs, bankruptcies) at higher rates. A mortgage broker who covers the specialist market can identify the lenders most likely to approve a specific case.
How long does adverse credit affect a mortgage application?
Defaults, CCJs and IVAs stay on the credit file for six years from the date of registration. Bankruptcies stay on the file for six years from the bankruptcy order. Missed payments are recorded for six years. Mainstream lenders typically want the most serious markers to be at least 3 years old; specialist lenders accept more recent issues at higher rates.
How can I improve my credit score before a mortgage application?
Check the credit reports at all three CRAs and dispute any inaccuracies, register on the electoral roll at the current address, settle or satisfy any outstanding defaults or CCJs, reduce credit utilisation below 30 percent of available limits, avoid new credit applications in the six months before the mortgage, and maintain clean payment history for at least 12 months.
Do mortgage applications affect my credit score?
An agreement in principle uses a soft credit search that does not affect the credit score. A full mortgage application uses a hard search that is visible to other lenders and can have a small short-term effect on the score. Multiple full mortgage applications in a short period can suggest financial pressure or shopping behaviour. The effect of a single full mortgage search is normally modest.
