As a rule, you should ask for professional accounting and or bookkeeping help as soon as you wonder if you need help!
Certainly when starting up, where they can advise on issues such as business requirements, software and VAT etc. A bookkeeper manages things on a day to day basis, managing invoices, bills and receipts, helping with VAT returns, payroll and pensions with HMRC and the pensions regulator; offering something that not all business owners may have the time or inclination to do for themselves.
An accountant then takes over to prepare reports, year end statutory accounts, offer more practical business advice based on the business transactions, making suggestions on any improvements and assisting the business owner with all legal obligations with HMRC and Companies House etc.
