Outsourced vs In-House Bookkeeper: The Real Cost Comparison for UK SMEs

Most business owners compare a bookkeeper's salary with an outsourced monthly fee and stop there. That comparison is misleading. A salary is only the starting point of what an employee costs, and an outsourced fee often covers far more than the hours you think you're buying. This guide walks through the numbers for UK small and medium-sized businesses, so you can decide with the full picture.

What an In-House Bookkeeper Really Costs

Employed bookkeepers in the UK typically earn between £24,000 and £35,000, depending on experience. Take a mid-range £30,000 hire as an example. Employer costs sit on top of that:

• Employer National Insurance: 15% on earnings above the £5,000 secondary threshold, which is £3,750 on a £30,000 salary.
• Workplace pension: the 3% minimum employer contribution on qualifying earnings adds about £713.
• Salary, NI and pension together: roughly £34,463.

That is before the costs owners tend to forget:

CostTypical annual estimateAccounting software seats and add-ons£300 – £1,000Laptop, desk, equipment£500 – £1,500 (first year)Recruitment (advert or agency fee)£500 – £6,000 (one-off)Training and CPD£300 – £600Holiday, sickness and coverHard to price, but realManagement timeYour hours, at your rate

These extras are planning estimates, not fixed figures. Your actual costs will vary.

Realistically, a £30,000 bookkeeper costs a UK business £36,000 to £40,000 in year one and about £35,000 to £37,000 a year after that.

A note on the Employment Allowance. Eligible employers can claim up to £10,500 off their employer NI bill. This doesn't apply to every business. For example, it isn't available where the director is the only employee paid above the secondary threshold. Check your own eligibility before relying on it.

What Outsourced Bookkeeping Costs

Outsourced pricing is more varied, because it scales with your business rather than with a fixed salary.

• Hourly: Freelance bookkeepers typically charge £20 to £50 per hour.
• Fixed monthly retainer: Small UK businesses usually pay £150 to £600 a month, rising to £600 to £950 or more for higher transaction volumes.
• Per transaction: typically £1 to £2 per transaction, which suits low-volume businesses but gets expensive quickly for high-volume ones such as e-commerce.

As a rough guide by business type:

Business typeTypical monthly costAnnual costSole trader or micro business£50 – £150£600 – £1,800Small limited company£100 – £300£1,200 – £3,600Growing SME (payroll, VAT, more transactions)£250 – £600£3,000 – £7,200Larger or multi-entity SME£600 – £2,500+£7,200 – £30,000+

Figures are indicative. Always confirm what a quote includes, as scope varies widely.

Side-By-Side: A Typical Small Limited Company

Take a limited company with 10 employees and around 250 to 300 transactions a month, needing bookkeeping, VAT returns, payroll and monthly management reports.

In-house (full-time)OutsourcedSalary or fees£30,000£4,800 – £7,200 (£400 – £600/month)Employer NI + pension~£4,460IncludedSoftware, equipment, training£1,100 – £3,100Usually included or minimalCover for holidays and sicknessExtra cost or disruptionIncludedApproximate annual total£35,500 – £37,500£4,800 – £7,200

For this profile, outsourcing costs roughly 80% less. Even a generous outsourced package at £1,000 a month (£12,000 a year) comes in far below one full-time hire.

Why the Gap Is so Large

You are buying output, not hours. A business with 250 transactions a month doesn't need 37.5 hours a week of bookkeeping. It may need 10 to 15 hours. An in-house employee is paid for the whole week, and an outsourced provider spreads capacity across many clients.

You also get resilience. If your in-house bookkeeper is off sick or leaves, your books stall. With an outsourced team, the work continues.

When In-House Makes Sense

Outsourcing isn't always the answer. Hiring in-house can be the better choice when:

• Volumes are high. Around 1,000+ transactions a month, or several entities, can justify a dedicated person or team.
• You need daily hands-on finance work. Chasing invoices, approving payments and supporting operations may need someone on site.
• Your systems are highly bespoke. Heavy customisation or complex internal processes can be easier to manage with a dedicated employee.
• You're at the point of a finance function. Once you need a finance manager or controller, a bookkeeper is one part of a larger team.

A middle option is a part-time employee (around 20 hours a week). Part-time in-house roles are often around £12,000 to £18,000 a year plus NI and pension. That's cheaper than full-time, but you still carry recruitment, cover and management burdens.

Hidden Factors That Change the Maths

Making Tax Digital. MTD for Income Tax brings quarterly digital reporting for sole traders and landlords, with the income threshold falling to £30,000 in April 2027 and £20,000 in April 2028. An outsourced provider already working on MTD-compatible software can absorb this. Otherwise it becomes extra training and admin for your in-house hire. Some providers may also adjust fees for the additional quarterly work.

Error and penalty risk. Late VAT returns or poor records can lead to HMRC penalties and interest. A specialist team with checks and controls can reduce this, but only if you confirm who is responsible for what.

Data security. With any outsourced provider, ask about GDPR compliance, where data is stored and who has access.

Management overhead. An employee needs supervision, appraisals and cover. Outsourcing shifts most of that to the provider, which frees up your time. Owners often undervalue this.

Questions to Ask Before You Decide

1. How many transactions do we process a month, and is that likely to grow?
2. What exactly is included in the fee: VAT, payroll, management accounts, year-end prep?
3. How is the work supervised, and who is my named contact?
4. What are the notice periods and any onboarding costs?
5. Which accounting software do they use, and is it MTD-compatible?

The Bottom Line

For most UK SMEs with modest transaction volumes, outsourced bookkeeping costs a fraction of a full-time hire. Once you include NI, pension, software, cover and management time, an in-house bookkeeper on £30,000 costs around £35,000 to £40,000, while a typical outsourced package for a small limited company sits at £150 to £600 a month. In-house only wins once volumes, complexity or the need for on-site finance support reach the point where a dedicated person is fully used.

Before you commit either way, get two or three outsourced quotes and cost your own in-house scenario line by line.

Disclaimer: This article is general information, not financial or tax advice. Rates, thresholds and allowances change, so check current HMRC guidance or speak to a qualified accountant.

FAQ

Is outsourced bookkeeping cheaper than hiring in-house in the UK?
For most small businesses, yes. A full-time employee costs around £35,000 or more once NI and pension are added, while typical outsourced retainers for small firms are a few hundred pounds a month.

How much does a bookkeeper cost per month in the UK?
Outsourced bookkeepers usually charge between £100 and £950 a month depending on size and scope. Hourly rates are typically £20 to £50.

What are the on-costs of an in-house bookkeeper?
Employer NI at 15% above £5,000, a minimum 3% employer pension contribution, software, equipment, training, recruitment and cover for absence.

When should I move from outsourced to in-house?
When your transaction volumes, number of entities or day-to-day finance needs are large enough to fully occupy a dedicated hire.