The short version: Your credit score is a number that tells lenders how reliably you’ve handled credit in the past. It directly affects whether you get approved for mortgages, loans, and phone contracts — and at what interest rate. A higher score means cheaper borrowing. The good news: credit scores can be improved, and most of the things that help are simple habits rather than financial tricks.
Most people know they have a credit score. Very few know what’s actually in it, why it matters beyond just “getting credit cards,” or what they can do to improve it.
Which is a shame — because your credit score quietly affects things most people don’t expect. Things like your mobile phone contract. Your car insurance premium. Whether your landlord accepts your application.
I spent ten years working in financial services at JPMorgan, Monzo, Starling, and Barclaycard. Credit decisions were part of my world. Here’s everything you actually need to know.
What is a credit score and who calculates it?
A credit score is a number generated by credit reference agencies (CRAs) based on your credit history. In the UK, the three main CRAs are Experian, Equifax, and TransUnion. Each uses a slightly different scoring model, so your score will look different on each one.
Lenders use this data — along with their own internal criteria — to decide whether to approve you for credit and what rate to offer you. They do not all use the same CRA, which is why you might get approved by one lender but not another.
What’s actually in my credit score?
The main factors that affect your score are:
| Factor | What it looks at | Impact |
|---|---|---|
| Payment history | Have you paid on time? Any missed or late payments? | Very high |
| Credit utilisation | How much of your available credit are you using? | High |
| Length of credit history | How long have your accounts been open? | Medium |
| Credit mix | Types of credit (loans, cards, mortgage) | Lower |
| New credit applications | How many hard searches in the last 12 months? | Medium |
| Electoral roll | Are you registered to vote at your address? | Medium — easy win |
How does my credit score affect my mortgage?
This is the big one. A good credit score means access to the best mortgage rates — which on a £200,000 mortgage can be the difference between paying hundreds less per month compared to someone with a poor score. Over a 25-year term, that difference is tens of thousands of pounds.
If you’re planning to buy a home in the next two to three years, your credit score matters enormously — and you have time to improve it meaningfully before you apply.
Does a credit score affect car insurance or renting?
Yes, more than most people realise. Some car insurers run a soft credit check as part of setting your premium — people with lower credit scores can be quoted higher premiums. Landlords and letting agents routinely run credit checks, and a poor score or missed payments can lead to a rejected application even if you can clearly afford the rent.
Your credit score isn’t just about borrowing. It’s a financial passport.
How can I improve my credit score?
- Register on the electoral roll. This is the single quickest win. Takes five minutes at gov.uk/register-to-vote.
- Pay everything on time. Set up direct debits for at least the minimum payment on all credit products. Even one missed payment can stay on your file for six years.
- Keep credit utilisation low. Try to use no more than 30% of your available credit limit at any time. If your limit is £2,000, keep the balance under £600.
- Don’t close old accounts. Length of credit history matters. An old card you rarely use but keep open is working in your favour.
- Avoid multiple applications in a short window. Each hard search slightly dips your score. Space applications out by at least three months where possible.
- Check your file for errors. Mistakes happen — wrong addresses, accounts that aren’t yours, payments marked as missed when they weren’t. Dispute any errors with the CRA directly.
Where can I check my credit score for free?
You can check your credit report for free with all three main CRAs. Experian, ClearScore (which uses Equifax data), and Credit Karma (TransUnion) all offer free access with no hidden charges. Checking your own score never affects it — that’s a soft search, not a hard one.
Mia’s story: five minutes that changed her mortgage application
Mia, 28, had been renting for six years and was finally in a position to buy. She checked her credit score and found it sitting in the “fair” band — not terrible, but not where she wanted it for a mortgage application.
Digging into her report, she found two issues: she wasn’t registered to vote at her current address, and an old mobile phone account showed a late payment she was certain she’d made on time. She registered on the electoral roll and raised a dispute with the CRA.
Three months later, after registering and getting the payment corrected, her score had moved from “fair” to “good.” Her mortgage broker told her it opened up meaningfully better rate options. She’d done both things in under an hour total.
The M&G System: do this this week
- Check your credit file on ClearScore, Experian, and Credit Karma — all free. Look for any errors, missed payments, or accounts you don’t recognise. Dispute anything wrong immediately.
- Register on the electoral roll if you haven’t already. Go to gov.uk/register-to-vote. Five minutes. Immediate impact.
- Set a direct debit for the minimum payment on every credit product you hold. Even if you pay in full each month, the safety net means you’ll never accidentally miss a payment.
If you’re not sure where your finances stand overall — credit score included — the free Financial MOT at moneyandgrowth101.com/tools/ gives you a full picture in under ten minutes.
And if you’d like to talk through how your credit situation fits into your bigger money goals, book a free Money Clarity Call. It’s 20–30 minutes, no pressure, just clarity.
Two ways to go further
If you would rather have the whole thing in order instead of one post at a time, that is what the book does.
Money & Growth 101 — the no-fluff UK guide to clearing debt and building real wealth.
Prefer to talk it through first? A Money Clarity Call is 20–30 minutes, free, and there is no pressure either way.
Frequently asked questions
What’s a good credit score in the UK?
Each CRA has a different scale. On Experian (0–999), “good” starts around 881. On ClearScore/Equifax (0–1,000), “good” is roughly 531 and above. On Credit Karma/TransUnion (0–710), “good” is around 566 and above. The specific number matters less than which band you’re in and the direction it’s moving.
How long does a missed payment stay on my credit file?
Six years from the date of the missed payment. Its impact on your score reduces over time — a missed payment from five years ago matters much less than one from last month. The practical advice: don’t miss any from this point forward.
Can I improve my credit score quickly?
Some things improve it quickly: registering on the electoral roll, correcting errors, and paying down high balances. Others take time: building a payment history, lengthening your credit age. Realistically, a meaningful improvement takes three to six months of consistent behaviour.
Does being in a relationship affect my credit score?
Not by itself. However, if you open a joint financial product (joint mortgage, joint loan, joint bank account with an overdraft) with someone, you become “financially linked.” Their credit history then becomes relevant to your applications. This can help or hinder depending on their score.
Do soft searches affect my credit score?
No. Soft searches — such as checking your own score, or eligibility checkers — are not visible to lenders and do not affect your score. Only hard searches (full credit applications) are visible to lenders and have a small impact. Always use an eligibility checker before applying for credit.
Related reading: How to Clear Debt on a Normal UK Salary · The M&G System · How to Make a Spending Plan That Actually Works
Mustafa Alsoodany is the founder of Money & Growth 101. By day he’s worked in financial crime and compliance at banks and fintechs — JPMorgan, Monzo, Starling and Barclaycard among them — and holds the ICA Advanced Certificate in Anti-Money Laundering at Distinction. He started Money & Growth 101 to do the opposite of the day job: make money plain, jargon-free and genuinely doable for people in their 20s and 30s who were never taught it.
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