How many years before hire companies destroy their records then? I have records for my business going back to when I started it over seven years ago for example.
Companies can keep records as long as they wish. I worked for a multi-national oil company and their records went back to when they arrived in the UK in the 1980's to gather North Sea oil. All stored with an archive company at great expense.
Legally financial records should be kept for 6 years in the UK as HMRC can investigate up to 6 years ago. But. If they find a discrepancy within those 6 years resulting in an underpayment of tax they can assume the same discrepancy existed previously and demand the back tax they assume you owe. If you've destroyed your records you can't prove they're wrong.
Companies can keep records as long as they wish. I worked for a multi-national oil company and their records went back to when they arrived in the UK to gather North Sea oil. All stored with an archive company at great expense.