If you are in business as a self-employed sole trader or in a partnership you need to keep a following accounting records: 

•Record all sales and other business income and retain the records, for example, invoices, bank statements and paying-in slips. 

•Record all purchases and other business expenses as they arise and ensure you keep invoices and receipts. 

•Keep a record of all purchases and sales of assets which are used in your business. 

•Record all amounts taken out of the business bank account, from cash or stock, for your own personal use. 

•Record all amounts paid into the business from your own personal funds, for example, paying for stock with your personal card. 

•If you are claiming mileage allowance for business trips you must record details of the journey, such as date, number of miles travelled, destination and purpose of the business trip. 

It is very important you keep your personal records separate from those for your business.