There are several things that can affect your credit score:
Names – If there are variations of your name on your report, it may be more difficult to verify your identity.
Addresses – banks and lenders look at your whole address history and the credit data attached to each address (including addresses you haven’t given us). They use this data to calculate your score, so if any addresses are missing, your report won’t be completely accurate.
Electoral roll – if your current electoral roll details are not listed on your report, it makes it more difficult for banks and lenders to verify your identity and this may lower your score.
Bankruptcies, County Court Judgments (CCJs), Individual Voluntary Arrangements (IVAs) – any bankruptcies, CCJs or IVAs on your report will negatively impact your credit score because you’ll appear less likely to pay back any credit or loans.
Current debt – Accounts with high levels of current debt could decrease your score.
Missed payments – recent or historic missed payments on your credit accounts cause a lender to doubt your ability to pay off any future debt.
Short-lived credit accounts – If all your credit accounts have only been open for a short time this can lower your credit score as it suggests instability. Your score may also go down when an account is closed and/or removed from your report because the average age of your accounts will decrease
'Credit application searches' – Also known as 'hard' searches, these appear when a lender performs a search on your credit report (i.e. a background check on your credit history). Too many credit application searches on your report indicates that you’ve applied for several credit accounts. This lowers your score as it suggests to lenders that you may rely heavily on credit and might struggle to make repayments.
Financial Connections – If you apply for finance with someone (e.g. you hold a joint credit card or mortgage) they become linked to your credit report. Though this doesn’t necessarily decrease your score, their credit history may be taken into consideration when you apply for credit.