Outsourced accounting and a fractional Financial Controller are often presented as alternatives, and they are not. An outsourced bureau does the work: it processes transactions, runs payroll, files VAT returns and produces a monthly pack. A fractional Financial Controller owns the outcome: they review the numbers, design the controls, run the close and tell you when something is wrong. Businesses that buy one expecting the other end up disappointed for predictable reasons. A bureau will not challenge your pricing, and a fractional FC should not be coding your purchase invoices.
This guide sets out what each model actually delivers, what each typically costs, where businesses go wrong, when one is enough and when you need both. If you already know you need senior finance oversight, our fractional Financial Controller recruitment page explains how we place them, and what is a fractional Financial Controller? covers the role in more depth.
The core distinction
An outsourced accounting bureau may be an accountancy practice, a bookkeeping firm or an offshore team. It does the production work: bookkeeping, bank reconciliations, payroll, VAT returns and, in many cases, a monthly management accounts pack produced to a standard template. It is priced per month against a defined scope, and it scales predictably with transaction volume.
A fractional Financial Controller is a qualified accountant, usually ACA, ACCA or CIMA, who works for your business one or two days a week on an ongoing basis. They may do very little processing themselves. What they provide is review, judgement, control design and accountability: someone who will notice that margin has moved for a reason nobody has spotted, that an account has not been reconciled since March, or that a control gap needs closing before the auditors find it.
The difference in one line: the bureau produces the numbers; the fractional FC is answerable for them.
Side-by-side comparison
| Outsourced bureau | Fractional FC | |
|---|---|---|
| What you buy | Processing and production | Accountability and judgement |
| Typical scope | Bookkeeping, VAT, payroll, standard pack | Close ownership, controls, review, board pack |
| Challenges the business? | Rarely | Yes, that is the point |
| Designs controls? | No | Yes |
| Attends your board? | No | Frequently |
| Knows your business | At transaction level | Commercially |
| Typical cost | £800–£3,000 a month | £2,000–£5,500 a month |
| Pricing basis | Scope and transaction volume | Days per week |
Costs vary with location, complexity and the seniority of the individual. For current day rates and retainers by region, see fractional FC rates UK.
What an outsourced bureau does well
A good bureau is efficient at volume, consistency and cost. Processing a thousand transactions a month reliably is exactly what a well-run bookkeeping operation does, and doing it in-house at that scale is rarely cheaper. Bureaux handle the statutory and compliance cycle: filing accounts at Companies House, VAT returns under Making Tax Digital, payroll and RTI submissions, and keeping the ledger current so a pack arrives on time.
Many bureaux are regulated practices supervised by a professional body such as the ICAEW or ACCA, which is worth checking before you appoint one. The limitation is structural rather than a matter of quality. A bureau is a supplier of a defined service; it does what is scoped, and it is not well placed to notice what is missing from the scope or to tell the owner something unwelcome.
What a fractional Financial Controller does well
A fractional FC is good at everything that needs judgement. A typical one-day-a-week engagement covers month-end close oversight and sign-off, review of the management accounts with commentary, balance sheet reconciliation management, the relationship with the external auditor, and maintenance of the financial controls. At two days a week it usually extends to producing board-ready management accounts, budgets and forecasts, oversight of the accounting system and proactive advice to the managing director.
The value is in the questions they ask. Are the numbers right, rather than merely complete? Does the accrual basis still make sense? Why did gross margin fall two points last quarter? Which control is missing, and what will it cost if it is not fixed? A fractional FC delivers that for roughly 35–55% of the all-in cost of a permanent Financial Controller, which is why it suits businesses where the FC-level work is real but does not yet fill a week. Our guide to when to hire a fractional Financial Controller sets out the usual signs.
Not sure which model you need? — 0204 553 8893
Tell us how your finance function runs today and we will tell you whether a fractional FC, a bureau, both or a permanent hire fits. Same working day response.
Where businesses get it wrong
Buying a bureau and expecting control
This is the most common mistake. A business outsources its bookkeeping, receives a monthly pack and assumes finance is handled. Then year-end arrives and the balance sheet has not been reconciled, because nobody asked the bureau to do it and it was never in scope. Bureaux do what is scoped; they do not take responsibility for what is missing.
Buying a fractional FC and expecting processing
The mirror image, and an expensive one. A qualified Financial Controller on a day rate spending their time coding invoices is poor value for the business and unsatisfying for the FC, and the engagement rarely lasts. If the transactional work is not covered, the FC either does it badly or not at all.
Treating a standard pack as management information
A template report produced from the ledger tells you what happened. It does not tell you why, or what to do about it. Our guide to management reporting that gets read explains the difference between a report and analysis.
Assuming either removes the need for internal ownership
Someone in the business still has to own purchase approvals, stock counts, sales information and the other inputs finance depends on. Neither a bureau nor a fractional FC replaces that.
The hybrid model: bureau plus fractional FC
For businesses of roughly £2m to £15m revenue, the arrangement that usually works best is both: a bureau handling production, with a fractional FC owning the outcome. The bureau processes transactions, runs payroll, files VAT and prepares a draft set of accounts. The fractional FC reviews it, owns the reconciliations, designs the controls, prepares the board pack and is accountable for the result.
A two-day fractional FC plus a mid-sized bureau typically costs £5,000–£7,000 a month, against roughly £9,000 a month fully loaded for a permanent Financial Controller plus an internal bookkeeper. Two conditions make it work:
- The FC has authority over the bureau’s output. They must be able to send work back, change the process and set the close timetable. A bureau that reports only to the founder, with the FC reviewing after the event, is the worst of both models.
- The scope split is written down. The gap between what the bureau does and what the FC does is exactly where things fall through, so agree in writing who owns each reconciliation, deadline and filing.
A variation that works well where the business already employs a management accountant is the in-house version of the same idea: internal staff handle the transactions and the fractional FC supervises them, which keeps knowledge inside the business. Our article on the hybrid model of a fractional FC and in-house management accountant covers that structure, and outsourced financial controller services explains the fully external version.
Control and audit considerations
The question an auditor, lender or investor will ask is not who processes the transactions but who is accountable for the numbers and the controls around them. A bureau-only arrangement often struggles to answer that well. Segregation of duties is weak when the same external team raises, approves and records entries, and nobody inside the business reviews the balance sheet in depth.
A fractional FC fills that gap. They document the close process, own the reconciliation index, set approval limits and system access, and prepare the audit file so the auditors can rely on it. Our guides to internal controls for growing businesses and optimising the month-end close show what good looks like. Directors remain responsible for keeping adequate accounting records under the Companies Act 2006, whichever model they choose, so it matters that someone qualified is checking.
When you only need one
- Bureau only: businesses under about £2m with simple transactions, no external reporting obligations and a founder who is genuinely comfortable with the numbers. Adding senior control at that scale is usually premature.
- Fractional FC only: businesses that already have competent internal transactional staff but no qualified oversight. The FC supervises the existing team instead of a bureau.
- Neither, hire permanently: where the combined requirement fills a full week, a permanent Financial Controller is usually better value. See our Financial Controller recruitment service and the Financial Controller salary guide.
- Short-term gap: if the need is cover for a departure, a year-end or a systems project, an interim Financial Controller is the better shape.
Our fractional FC readiness assessment works through which situation you are in.
Four questions to ask your bureau
- Is the balance sheet reconciled every month, and can you show me the evidence? The single most useful question, and the answer is often no.
- Who reviews the output before it reaches me? A named, qualified reviewer is a good sign.
- What is explicitly outside your scope? Ask for it in writing.
- What would you tell me if you thought something was wrong? The answer shows whether you have bought production or judgement.
Frequently asked questions
Is a fractional FC cheaper than outsourced accounting?
Not usually, because they buy different things. A bureau is typically £800–£3,000 a month for processing; a fractional FC is typically £2,000–£5,500 a month for oversight. The useful comparison is the combination against a permanent FC plus bookkeeper, where the hybrid model is usually cheaper.
Can a fractional FC manage our existing bureau?
Yes, and that is one of the most common engagements we place. The key is giving the FC clear authority over the bureau’s timetable and output from day one.
How many days a week does a fractional FC need?
One day a week suits most businesses of £2m–£5m with a bureau in place; two days suits £5m–£15m or businesses with investors, lenders or a complex audit. Our guide to engagement models, days and retainers covers scoping.
How quickly can you place a fractional FC?
Fractional and interim searches typically produce candidates within days, because we work from an existing network of portfolio Financial Controllers. Call 0204 553 8893 or email recruitment@accountancycapital.co.uk.
Adrian Lawrence FCA — Founder, Accountancy Capital
Fellow of the ICAEW | Chartered Accountant holding an ICAEW practising certificate | Part of FD Capital Group
Adrian is a former listed-company Finance Director with a BSc from Queen Mary College, University of London. The conversation he has most often with £5m–£10m businesses is that they have outsourced their accounting and cannot understand why finance still feels out of control. His advice is usually to keep the bureau for processing and add a day or two a week of someone accountable for the result.
Related Pages and Resources
Fractional Financial Control
Accountability without a permanent hire.
What Control Looks Like
Close, controls and reporting.
→ Designing financial controls
Fractional Financial Controllers — 0204 553 8893
We place fractional, interim and permanent Financial Controllers across the UK, including FCs who manage an existing bureau. Same working day response to every brief.