Fixed monthly fees
The dominant model for small and medium clients: a flat monthly amount covering a defined scope, usually with a volume assumption stated in the engagement letter. It gives the client predictability and gives the provider an incentive to work efficiently. The risk lies in volume assumptions that are set too low at the start, producing an unexpected increase at renewal.
Volume and per-transaction pricing
Common for bookkeeping and payroll, where the cost driver is countable: invoices, bank lines, payslips, employees per country. Volume pricing is transparent and scales fairly, but it requires the client to forecast volume accurately and to understand how documents are counted.
Annual or package pricing
Some providers price the whole compliance calendar as an annual package, including the statutory accounts and the tax return. This suits companies with a stable profile, because the client pays once and the provider absorbs seasonal peaks. It suits providers with good internal planning, and it makes year-end surprises less likely.
Hourly and time-based pricing
Still the norm for advisory work, project work and unusual transactions, and used by many smaller practices for everything. The comparison question is not the hourly rate itself but what is included in a standard hour: which person's time, whether review time is charged twice, and how time is recorded.
Quoted or individually negotiated fees
Many providers publish no prices at all and quote per client. In this guide such providers are recorded as 'Pricing is not publicly listed', which is a factual statement about disclosure rather than a comment on value. Where a provider does publish a starting price, the figure is recorded with its source and the date it was checked, and it should always be confirmed directly before you rely on it.
Applying this
Whatever the model, the fee schedule should name each recurring deliverable, state the assumptions on which the price depends, and set out the rate that applies when the assumptions change.