What Affects Your Credit Score?

How Credit Scores Are Calculated

Your credit score is calculated by each of the three UK credit reference agencies — Experian, Equifax and TransUnion — using proprietary algorithms that weigh dozens of data points from your credit file. While the exact formulas are confidential, the agencies have broadly confirmed which factors carry the most weight.

It is helpful to think of the factors in three tiers of influence:

Impact Level	Factors
Highest	Payment history, public records (CCJs, defaults, bankruptcy)
High	Credit utilisation, amount of outstanding debt
Medium	Length of credit history, types of credit, hard searches, electoral roll
Lower	Address stability, total available credit, financial associations

Understanding each factor and its relative weight helps you prioritise where to focus your efforts. A single on-time payment matters far more than being on the electoral roll, but the electoral roll is an easy win that many people overlook.

Payment History (Highest Impact)

This is the most important factor in your credit score. All three agencies give the greatest weight to whether you pay your bills and credit commitments on time, every time.

Your credit report records a month-by-month payment status for each credit account going back six years. Even one missed payment can cause your score to drop significantly — Experian estimates a single late payment can reduce your score by up to 130 points on their 0–999 scale.

What Counts as a Late Payment?

A payment is typically reported as late if it is more than 30 days past the due date. Some lenders report at 14 days, but most use the 30-day threshold. The later the payment, the more damaging it is:

• 30 days late — noticeable negative impact
• 60 days late — more significant impact
• 90+ days late — severe impact; may trigger a default
• Default — usually issued after 3–6 missed payments; one of the most damaging entries

How to Protect Your Payment History

• Set up direct debits for at least the minimum payment on all credit products
• Use calendar reminders as a backup for non-direct-debit bills
• If you are going to miss a payment, contact the lender before the due date — many will offer breathing space without reporting it
• Consider a budgeting app that alerts you before payments are due

Credit Utilisation (High Impact)

Credit utilisation is the percentage of your total available credit that you are currently using. It applies primarily to revolving credit products such as credit cards and overdrafts.

For example, if you have two credit cards with a combined limit of £10,000 and a combined balance of £3,000, your utilisation is 30%. Credit agencies assess this both per-card and across all cards combined.

What Is the Ideal Utilisation?

Utilisation Rate	How Agencies View It
0%	No credit activity — shows no evidence of responsible borrowing
1–25%	Ideal range — shows you use credit but are not reliant on it
26–50%	Acceptable but could be improved
51–75%	Starting to look stretched — likely to lower your score
76–100%	High risk — significant negative impact on score

How to Manage Utilisation

• Pay down balances before the statement date (the date your balance is reported to agencies)
• Spread spending across multiple cards rather than maxing out one
• Request a credit limit increase — but only if you will not be tempted to spend more
• Consider a 0% balance transfer card to help clear high-interest balances

Length of Credit History (Medium Impact)

Agencies consider both the age of your oldest credit account and the average age of all your accounts. A longer history gives lenders more data to assess your behaviour, which is inherently less risky than a short history.

This is why closing old accounts can sometimes hurt your score. If you close a credit card you have had for 15 years, you remove 15 years of positive history from your file. If your remaining accounts are only a few years old, your average account age drops significantly.

Tips

• Keep your oldest credit account open, even if you rarely use it
• If there is an annual fee on an old card, ask the provider to switch you to a no-fee version rather than closing it
• Avoid opening lots of new accounts at once, as this lowers your average account age

Types of Credit (Medium Impact)

Having a mix of different credit types demonstrates that you can manage various financial commitments. The types that typically appear on your report include:

• Revolving credit — credit cards, store cards, overdrafts
• Instalment credit — personal loans, car finance, student loans
• Secured credit — mortgages
• Service credit — mobile phone contracts, some utility accounts

You do not need to have all of these — and you should never take on credit you do not need just to diversify your mix. However, if you have only ever had one type of credit (say, just a credit card), gradually adding another type that you genuinely need can be beneficial.

Hard Searches (Medium Impact)

A hard search (also called a hard inquiry or hard footprint) is recorded every time you formally apply for credit. Each hard search is visible to other lenders and can temporarily lower your score.

The impact of a single hard search is usually modest — perhaps 5 to 15 points on the Experian scale. However, multiple searches in a short period are cumulative and can signal to lenders that you are in financial difficulty or are being rejected elsewhere.

Hard Searches vs. Soft Searches

Hard Search	Soft Search
Triggered by a formal credit application	Triggered by eligibility checks, self-checks, identity verification
Visible to other lenders	Only visible to you
Can lower your score	No impact on your score
Stays on file for 2 years (visible to lenders for 12 months)	Stays on your file only; not visible to lenders

How to Minimise Hard Searches

• Always use eligibility checkers before applying — most comparison sites and lenders offer them
• Space applications at least three months apart
• If you are rate shopping for a mortgage, try to submit all applications within a 14-day window — some scoring models treat this as a single search
• Remember that checking your own credit is always a soft search

Electoral Roll Registration (Medium Impact)

Being registered on the electoral roll at your current address is one of the easiest ways to boost your credit score. It helps credit agencies and lenders verify your identity and confirm where you live.

According to Experian, people who are not on the electoral roll may see their score reduced by up to 50 points. Registering is free and takes under five minutes at GOV.UK.

If you are not eligible to register to vote (for example, non-UK/Commonwealth nationals), you can provide proof of address directly to each credit agency. This does not have quite the same positive effect as electoral roll registration, but it is better than nothing.

Public Records: CCJs, Defaults & Insolvency (High Impact)

Negative public records have some of the most severe and long-lasting effects on your credit score. These include:

County Court Judgments (CCJs)

A CCJ is issued when a creditor takes you to court for an unpaid debt and the court rules in their favour. CCJs remain on your credit file for six years, regardless of whether you pay them. However, paying a CCJ within one calendar month of the judgment allows you to apply to have it removed from the Register of Judgments entirely.

A CCJ can reduce your Experian score by 250 points or more and will make many mainstream lenders unwilling to offer you credit.

Defaults

A default is recorded when a lender considers that you have broken the terms of your credit agreement, usually after three to six consecutive missed payments. The lender must send a “default notice” giving you 14 days to bring the account up to date before registering the default.

Defaults stay on your file for six years from the date they are registered. Their impact lessens over time, and some specialist lenders will consider applicants with defaults that are more than two to three years old.

Insolvency

Bankruptcy, Individual Voluntary Arrangements (IVAs) and Debt Relief Orders (DROs) all appear on your credit file for six years. These are the most damaging entries possible and will severely limit your access to credit during that period. After the six-year period, they are removed and your score can begin to recover — though it takes time to rebuild.

Financial Associations (Variable Impact)

When you open a joint financial product with another person — such as a joint bank account, joint mortgage, or joint loan — you become financially associated on each other’s credit files. This means lenders may consider the other person’s credit history when assessing your application.

If your associated person has excellent credit, this is neutral or possibly slightly positive. But if they have poor credit, missed payments or defaults, it could negatively affect your ability to get approved.

Key Points

• Merely living at the same address does not create a financial association
• Being married or in a civil partnership does not automatically create a link unless you have joint credit
• You can request a financial disassociation once the joint account is closed
• Each credit agency must be contacted separately, as they do not share disassociation requests

Address Stability (Low–Medium Impact)

Lenders view stability as a positive signal. Living at one address for a longer period suggests lower risk than frequent moves. While this is not one of the highest-weighted factors, it contributes to the overall picture.

If you do move frequently, make sure to:

• Update the electoral roll immediately at your new address
• Update all your financial providers with your new address promptly
• Check that old addresses are not still listed as current on your credit report

Total Available Credit (Low–Medium Impact)

The total credit available to you across all accounts is a factor, though its impact is less straightforward. Having a very high total credit limit can make some lenders nervous (even if you are not using it), because theoretically you could draw it all down at any time.

Conversely, having very little available credit may suggest you are new to borrowing or that previous lenders have only been willing to offer small limits. The ideal position is somewhere in the middle — enough available credit to show you are trusted, but not so much that it looks like a risk.

Common Myths: What Does NOT Affect Your Score

There are numerous misconceptions about credit scores in the UK. The following things do not affect your credit score:

• Your income or salary — credit agencies do not know what you earn. Lenders may ask about your income on an application form, but it is not part of your credit score calculation.
• Your savings — bank balances are not reported to credit agencies and are not factored into your score.
• Council tax arrears — unless they result in a CCJ, council tax arrears do not appear on your credit file.
• Parking fines or speeding tickets — these do not appear on credit reports unless they escalate to a CCJ.
• Checking your own credit score — this is always a soft search with zero impact.
• Your race, religion, gender or marital status — credit agencies do not hold or use this information. The Equality Act 2010 makes it illegal for lenders to discriminate on these grounds.
• Student loans — UK student loan repayments through HMRC do not appear on your credit file and do not affect your score. However, they may be considered in affordability assessments by mortgage lenders.
• Using a debit card — debit card transactions are not reported to credit agencies as they do not involve borrowing.

Why Scores Differ Between Agencies

It is completely normal to have different scores with Experian, Equifax and TransUnion. This happens for several reasons:

• Different scales — Experian uses 0–999, Equifax uses 0–1000, TransUnion uses 0–710. The numbers are not directly comparable.
• Different data — not all lenders report to all three agencies. A credit card provider might report to Experian and Equifax but not TransUnion, meaning one agency lacks data that the others have.
• Different algorithms — each agency has its own proprietary model that weighs factors differently.
• Different update cycles — data arrives at different times, so at any given moment, each agency may have slightly different information about your accounts.

The practical takeaway is that you should check your score and report with all three agencies. Use MSE Credit Club for Experian, ClearScore for Equifax, and Credit Karma for TransUnion. All are free. For a detailed look at what each band means, review our guide on what is a good credit score.

What You Can Do About Each Factor

Here is a summary of every factor and the specific action you can take to improve it:

Factor	Impact	Action
Payment history	Highest	Set up direct debits for all credit commitments; never miss a payment
Credit utilisation	High	Keep below 25–30% across all cards; pay before statement date
Public records	High	Pay CCJs within one month if possible; avoid defaults by contacting lenders early
Credit history length	Medium	Keep oldest accounts open; avoid opening many new accounts at once
Credit mix	Medium	Maintain different credit types if you naturally need them; do not borrow unnecessarily
Hard searches	Medium	Use eligibility checkers; space applications 3+ months apart
Electoral roll	Medium	Register at GOV.UK — takes five minutes
Financial associations	Variable	Request disassociation from ex-partners once joint accounts are closed
Address stability	Low–Medium	Update address promptly when you move; re-register on electoral roll
Available credit	Low–Medium	Close unused accounts selectively; request limit increases only if needed

For step-by-step guidance on implementing these actions, review our detailed guide on how to improve your credit score.

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