Hiring a part-time bookkeeper: what will it really cost your practice?

Define the workload and paid hours you actually need

Start with a task list rather than a job title. Review your client commitments and identify work you could hand over: transaction processing, bank reconciliations, requesting missing records, maintaining schedules and preparing files for review. Record the time you currently spend, how often the task recurs and when it must be completed. Mark any backlog separately so you do not mistake a temporary pile of work for permanent demand.

Next, decide what the employee would own and what you would retain. Someone preparing reconciliations for your review is a different hire from someone managing client queries independently. Match proposed working days to your delivery calendar, including when clients normally provide records and when you can answer questions. Build a paid-hours estimate that includes internal communication and training, rather than buying only the hours currently visible on client jobs.

• Recurring delivery: work already supported by continuing client engagements.
• Temporary work: clean-ups, migrations and overdue records.
• Owner-retained work: technical judgement, final review and sensitive client conversations.
• Support time: handovers, training, internal meetings and queries.

Calculate gross pay and check the applicable minimum wage

Choose a pay basis that fits the role, then calculate gross pay using the actual paid hours and contractual arrangements you intend to offer. For a salaried role, confirm the full-time hours behind any advertised salary before applying a part-time proportion. For an hourly role, have your payroll adviser check how paid hours and leave arrangements feed into the annual and monthly budget.

Benchmark comparable responsibilities, not just similar titles. The supplied council vacancy describes an accountant role, while the commercial bookkeeping pricing article discusses fees charged to clients. Neither should be treated as a direct wage benchmark for your part-time employee. Look for current vacancies with a similar level of independence, software knowledge and client responsibility.

Before agreeing pay, check GOV.UK for the minimum wage rate applicable to the worker and the relevant start date, together with guidance on working time and pay calculations. The supplied notes do not verify those official rates for publication. Likewise, do not cost proposed employment reforms as though they are already in force: confirm commencement dates and applicability through official guidance or a professional adviser.

Budget for employer National Insurance and workplace pensions

Ask your payroll provider to model employer National Insurance using the proposed pay, pay frequency and applicable employee category. Check the current rates, thresholds and any relief or allowance eligibility against GOV.UK. Keep the underlying employer cost visible and show any confirmed relief separately, rather than assuming it will remove the cost throughout the budget period.

For workplace pensions, check The Pensions Regulator’s official guidance and your scheme terms for the employee assessment, relevant earnings basis and applicable employer contribution. Have your adviser confirm the calculation; do not simply apply a remembered percentage to the full salary. Add payroll processing and pension administration charges where your provider will charge extra.

Keep employer costs distinct from deductions taken from the employee’s gross pay. Your hiring model should start with gross pay and add the employer’s additional costs, rather than counting employee deductions again. Where eligibility remains uncertain, run a cautious version without the unconfirmed saving before committing.

Allow for paid leave, absence cover and training time

Build a separate capacity calculation alongside the payroll calculation. Start with paid hours, then allow for leave, training, internal administration, meetings and a realistic absence contingency. What remains is your estimate of time available for client delivery—not a promise of immediate independent output. Check GOV.UK or your adviser for the holiday and sickness rules relevant to the working pattern and start date.

Avoid double-counting. Where your gross-pay budget already includes paid holiday, do not add that pay again as a separate expense. Instead, reduce available delivery hours and add only any genuine additional cover cost. Treat training similarly: the employee’s paid learning time belongs in the capacity model, while course fees and additional cover belong in the spending budget.

Plan how deadline-sensitive work will be covered. You might retain responsibility for urgent queries or arrange suitable temporary support. If you will provide the cover yourself, reserve that time explicitly rather than assuming it will fit around a full client workload. The same applies to checking work during the employee’s early months.

Add software, secure equipment and your own supervision

Ask suppliers what an additional employee will actually cost. Check accounting and practice software access, document management, email, payroll services and any training subscriptions you intend to provide. Scope a suitable secure working setup, including equipment, access permissions and support. Do not assume that an existing subscription or spare laptop is suitable without checking.

Separate initial spending from recurring costs. Obtain quotes for recruitment support, employment documentation advice, equipment and setup where needed. Then estimate your own time for interviewing, induction, reviewing reconciliations, answering questions and correcting work. Owner time may not create a new payment, but it still needs space in the delivery plan.

Maintain a cash-cost total and a separate economic-cost view that recognises your time. This makes it easier to see both what the bank account must fund and whether the hire is genuinely improving the practice’s return on effort. Avoid charging owner review time twice if it already sits within your client delivery costing.

Calculate the recurring client income needed to support the hire

Use your own client fees and delivery costs, rather than an advertised market rate. For each client group the employee would support, estimate fees less the other costs needed to deliver that work, such as client-specific software, subcontract support and retained review time. Exclude the new employee’s cost from that subtraction because you are about to test whether the remaining contribution can cover it.

The basic calculation is: required monthly client revenue = monthly hire cost ÷ contribution margin expressed as a decimal. Here, contribution margin means the share of revenue remaining after those other delivery costs, but before the hire. Use a consistent definition throughout. Add a chosen surplus or contingency to the hire-cost figure if you want the model to test more than break-even, and decide how initial spending will be funded.

For a simple client-count check, divide the monthly amount you need to cover by the average monthly contribution per suitable client, then round up. Next, test whether those clients’ delivery hours fit the employee’s realistic capacity and your review capacity. Separate existing work being transferred from genuinely additional income: handing over a client frees your time, but it does not itself increase revenue. State how you intend to use that freed time, and avoid relying on unsigned enquiries to meet payroll.

Stress-test affordability before making the commitment

Put the hiring budget into a cash forecast using expected payment dates, not just invoice dates. Include initial spending when it will leave the bank, payroll and associated payments when due, and your practice’s existing commitments. Keep a separate view of profit so that a positive average margin does not conceal a short-term funding gap.

Run a dependable-work case and a downside case. In the downside version, delay client receipts, extend the period of close supervision and remove income from unconfirmed work. Identify the lowest forecast cash balance and decide what reserve you would need to remain comfortable. If the plan only works with immediate productivity and prompt payment from everyone, revisit the hours, scope or timing.

Before proceeding, have the relevant employment arrangements and payroll assumptions checked professionally. Record which rates and rules were verified, when they were checked and which assumptions remain uncertain. After the employee starts, compare actual spending, delivery hours and review time with the budget so you can adjust workload before taking on more clients.

• What if an important recurring client pays later than expected?
• What if onboarding needs more owner time than planned?
• What if promised new work does not convert?
• What if absence cover or software access costs more than the initial estimate?
• Does the practice still have room for its existing bills and owner income needs?

How Capacity planning helps

HappyNoodle’s capacity planning helps you balance available time against committed work and expected revenue before taking on too much or leaving gaps. Use your hiring budget to decide how much realistic delivery time a part-time employee would add, allowing separately for training, leave and your own review work. Then compare that capacity with the client work already committed and the revenue you expect. Keep verified payroll calculations and the cash forecast alongside this exercise: capacity planning supports the workload decision rather than replacing those checks.