Neither pricing model is better in the abstract: each allocates risk differently, and the right choice depends on how predictable the work is. Fixed fees put the risk of overruns on the firm; hourly billing puts it on you. Once you see the two models as risk allocation rather than price levels, choosing between them for any given piece of work becomes straightforward.
This is one of the structural questions behind what an accountant costs a small business; here we take it head-on.
What each model really is
Fixed fee: a defined scope of work for a defined price, usually paid monthly. The firm absorbs variation. An awkward reconciliation costs them, not you. Their incentive is efficiency; your protection is the scope document.
Hourly billing: time recorded and charged as used. You pay for exactly the effort expended, no more and no less. The firm’s incentive is thoroughness; your protection is estimates, caps and regular reporting.
There is also a hybrid worth knowing: fixed fee for the recurring core, hourly (quoted first) for anything outside it. In practice this is what most good engagements become.
Where fixed fees win
Recurring compliance work is predictable in shape: annual accounts, a Self Assessment return, quarterly VAT, monthly payroll. The firm has done hundreds of them and can price the pattern. For this work fixed fees are genuinely better for the client:
- Budgeting is trivial because the cost is known a year ahead
- No meter anxiety: you ask questions when you should, which surfaces problems early
- The firm profits by being efficient, which pushes them towards good systems and clean data, pressure that benefits you too
The one caution: a fixed fee is only as good as its scope. A vague scope with a low price is not cheap; it is undefined. What belongs inside is covered in what a monthly accountancy fee should include, and what fixed-fee accountancy should include applies the same test to annual and one-off fixed fees.
Where hourly billing wins
Some work has genuinely unknowable scope: an HMRC enquiry whose direction nobody controls, untangling a disputed shareholding, forensic reconstruction, or advisory work that follows wherever the problem leads. A firm asked to fix-price this must price the worst case, so the fixed quote comes out higher than the likely hourly total. For open-ended work, hourly with safeguards is the honest structure:
- A written estimate before starting, revised if the picture changes
- A cap or check-in point beyond which work pauses for your approval
- Itemised time records so you can see where hours went
The change-request test
The sharpest way to compare two firms is to ask how each handles work that falls outside the agreed scope. Weak answers: “we usually just sort it out” (unpriced goodwill that becomes an argument later) or silence. Strong answer: out-of-scope work is identified, quoted, and only done once approved. This single question tells you more about future billing surprises than the headline price does. It belongs on the checklist in how to compare accountant quotes.
Choosing by type of work
| Type of work | Better model | Why |
|---|---|---|
| Annual accounts and tax returns | Fixed | Predictable shape, repeatable process |
| VAT, payroll, bookkeeping | Fixed | Recurring rhythm, volume known |
| Year-round advice line | Fixed (bundled) | Removes the disincentive to call |
| One-off complex projects | Hourly with estimate and cap | Scope honestly unknowable |
| HMRC enquiries | Hourly or insured | Direction outside anyone’s control |
| Catch-up and clean-up work | Fixed after assessment | Sizeable once the backlog is seen |
Frequently asked questions
Is a fixed fee always cheaper than hourly for the same work?
No: over a smooth year hourly might total less. You are paying a modest certainty premium, the same way insurance costs more than the average claim. Most owners consider budget certainty and unmetered access worth it.
What stops a fixed-fee firm doing the minimum?
The scope document and the renewal. A firm that under-delivers loses the client at review, and deliverables (filings, meetings, response times) are checkable. Put the checkables in writing.
Should I ever pay hourly for routine compliance?
Rarely. If a firm will only do your accounts hourly, ask why they cannot predict work they do constantly. It can be legitimate for a first year with unknown records, but should convert to fixed once they know you.
How do rate differences between staff levels work in hourly billing?
Firms charge different rates for different seniority. Ask who will actually do each part of the work and at what rate. A low headline rate applied by someone slow can out-cost a higher rate applied by an expert.
Can I switch models mid-engagement?
Yes, and engagements naturally evolve: hourly first year while the firm learns your business, fixed thereafter. Any switch should come with a fresh scope letter.
See how we structure it
Our small business accountancy service runs on fixed fees for the recurring core with out-of-scope work quoted before it starts, the model our fees page sets out in full. Request a quote and we will show you exactly where the line sits for your business.