Are there any hidden fees?

No. Your plan covers the routine work in full: every monthly or quarterly VAT return (UStVA), the annual return (Jahreserklärung), the EC sales list (ZM), every letter read and explained, routine letters answered for you. Standard is €1,299/year with the German registration included, or €99/month or €1,099/year if you already hold a German tax number. On monthly billing the annual return for a year is included when the plan covers July to December of that year; join later and that year's annual return is a one-time €599. If you need a new German VAT number and want nothing else, registration only is €499 one-time (no filing plan; our mandate ends when your tax number and VAT ID are issued). Everything outside the plan is an extra you choose, with its price shown before you buy: corrections (€99 each), catch-up returns for periods before you joined (€99 per past return), priority registration (€199), the filing extension (€199 per calendar year if you file monthly, included if you file quarterly), the setup review (€249), the stock module (€499 a year, pro-forma invoices included) and advisory work (€200 per hour, quoted first).