How long to keep records. You must normally keep records for at least 6 years from the end of the last company financial year they relate to. You may need to keep records longer if: 1  they show a transaction that covers more than one of the company’s accounting periods.2  the company has bought something that it expects to last more than 6 years, like equipment or machinery. 3  you sent your Company Tax Return late.ou must also keep any other financial records, information and calculations you need to complete your Company Tax Return. This includes records of all money: 1  spent by the company, eg receipts, petty cash books, orders and delivery notes.