A good accountant saves more than they cost in most circumstances. The challenge is that the title "accountant" is not protected in the UK — anyone can call themselves one. Knowing what credentials to look for and what questions to ask helps you find someone competent.
The main accountancy bodies in the UK are: ICAEW (Institute of Chartered Accountants in England and Wales), ACCA (Association of Chartered Certified Accountants), CIMA (Chartered Institute of Management Accountants), ICAS (Institute of Chartered Accountants of Scotland) and AAT (Association of Accounting Technicians, typically for bookkeepers and accounts preparation rather than advisory work).
Members of ICAEW and ACCA are regulated, must hold practising certificates, carry professional indemnity insurance and are subject to disciplinary procedures. Searching for a member practice on icaew.com or accaglobal.com is more reliable than searching Google alone.
Bookkeeping involves recording transactions, reconciling bank accounts and maintaining records. Accountancy covers preparation of accounts, tax planning, filing returns and advisory work. Many small businesses use a bookkeeper (cheaper) to maintain day-to-day records and an accountant for annual accounts and tax.