Outsource vs hire a bookkeeper in the UK
A practical decision framework for UK accountancy practices weighing up an in-house bookkeeper against a white-label outsourcing arrangement. Includes a break-even cost model, risk side-by-side, and three worked examples.
The two options at a glance
| Factor | In-house hire | Outsource |
|---|---|---|
| Fixed annual cost | £32–£55k | £0 |
| Marginal cost per job | £0 (within hours) | £55–£200 |
| Time to capacity | 8–12 weeks | Same week |
| Notice period | 1 month+ | None |
| Holiday / sick risk | High | None |
| Senior review built in | You do it | Yes (good providers) |
| Client face-time | Yes if needed | No (intentional) |
The break-even calculation
A junior in-house bookkeeper costs roughly £40,000 fully loaded (see our full cost breakdown) and provides ~1,650 chargeable hours/year. That's ~£25/hr fully loaded, or ~£30/hr once you account for typical utilisation.
Outsourced VAT and bookkeeping work in the UK costs roughly £15–£25/hr equivalent at typical job pricing. The crossover is around 40 hours of work per month:
- < 40 hrs/month → outsourcing always wins on cost.
- 40–80 hrs/month → break-even zone; outsourcing usually wins on risk and flexibility.
- > 80 hrs/month consistently → hiring becomes competitive.
Worked example 1 — Sole practitioner, 15 VAT clients
15 quarterly VAT clients = 60 returns/year ≈ 20 hours/month of bookkeeping and prep. Outsourced at ~£85/return = £5,100/year. Hiring is wildly uneconomic at this scale.
Worked example 2 — 4-partner firm with bookkeeping service line
80 monthly bookkeeping clients ≈ 120 hours/month. Outsourced at ~£110/client = £8,800/month = £105k/year. Two in-house bookkeepers cost ~£80k fully loaded. Hiring wins on pure cost, but loses on holiday cover, peak overflow and senior review.
Hybrid pattern: hire one bookkeeper for baseline, outsource overflow and peak filing weeks. This is what most growing UK practices end up doing.
Worked example 3 — Growing practice, MTD ITSA looming
From April 2026, sole traders earning over £50k file quarterly for Income Tax — a roughly 5x increase in submission volume per affected client. Most firms cannot hire fast enough for the wave. Outsourced capacity is the practical answer for the first 12–18 months.
The decision framework
- Forecast monthly hours. Be honest — don't include theoretical clients you haven't won yet.
- Below 40 hrs/month? Outsource. Hiring is uneconomic.
- 40–80 hrs/month and growing? Outsource for now; revisit at 80+.
- Above 80 hrs/month and stable? Hire for baseline; outsource overflow.
- About to ride an MTD wave? Outsource until the volume settles.
About FirmBooks
FirmBooks is a UK-managed white-label accounting service. We complete VAT returns, bookkeeping and year-end accounts for UK practices and return them under your firm's branding. Book a free meeting to learn more.
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