Legal Requirement –
Companies Act-under the new system of self assessment, the keeping of books is a must and it’s illegal not to.
Tax- to ensure the correctness of tax amounts paid and to be in a position to answer any queries relating to tax.
Control of Business – It’s almost impossible to know whether you are winning or losing, have to pay bills, people owe you money, etc. if you don’t keep books
Finance – If you require loans or finance you will need to show a set of accounts.
VAT / PAYE– records need to be kept for inspection