As soon as you decide to go into business, it is important for you to start keeping your records. This is because it’s much harder to work backwards at a later date. Although there are legal reasons for keeping accurate records, there are also good business reasons to do so.
Your business records should cover:
banking - cheque books, deposit books, bank statements
your income - invoices, credit card sales, debit and credit notes
your expenses - invoices for purchases, credit card purchases
cashbooks, petty cashbooks and wage books.
Please refer to Record Keeping for further details