The main drivers are transaction volume, number of entities, payroll headcount, VAT complexity, bookkeeping quality, software setup, filing deadlines, and whether you need advisory support alongside compliance. Clean records usually mean lower fees because the work is easier to review, explain and file.
Pricing also changes when the accountant is expected to take more responsibility. A once-a-year compliance job is different from monthly management accounts, cash flow planning, board-level conversations, software cleanup or hands-on workflow design. If the work affects decisions, tax risk, funding, hiring or reporting rhythm, the scope needs to reflect that.