Temporary Employment vs Fixed Term Contracts: Which is Right for Your Business Needs?

When a business needs finance capability for a defined period rather than permanently, it has four genuinely different routes — and they differ not just in cost but in employment status, legal obligations, notice arrangements and the calibre of person each attracts. Choosing between them casually is how businesses end up paying agency rates for work that suited a fixed-term contract, or offering an FTC to a day-rate interim who was never going to accept one. This guide sets out how each arrangement works in the UK, what each costs in practice, and which fits which need — written for employers hiring finance staff, where the distinctions bite hardest because the day-rate market at this level is well developed.

The four arrangements

Agency temporary worker. The individual is supplied by an agency and typically employed or engaged by it, not by you. You pay the agency an hourly or daily charge covering the worker’s pay, employment costs and the agency margin. Flexible in both directions, quick to arrange, no direct employment relationship — and the most expensive per day.

Fixed-term contract (FTC). The individual is your employee, on a contract with a defined end date or end event. They are on payroll, accrue holiday and statutory rights, and are protected by the Fixed-term Employees Regulations, which give them the right not to be treated less favourably than comparable permanent employees. Cheaper per day than agency temping, and the arrangement that best suits maternity cover and defined projects of six months or more.

Day-rate interim (contractor). An experienced professional engaged for a defined assignment, usually through their own limited company or an umbrella arrangement, paid a day rate. Not your employee. Standard at Financial Controller, Finance Director and specialist level, where the market is genuinely a contractor market — these individuals build careers from assignments and will rarely accept an FTC. IR35 status must be assessed properly, which is covered below.

Fractional. An ongoing part-time arrangement — one or two days a week indefinitely rather than full-time for a fixed period. Different in shape from the other three: it solves “we need this capability but not full-time”, where interim and FTC solve “we need this capability but not permanently”. Our guide to interim versus fractional finance covers the distinction in full.

The comparison

	Agency temp	Fixed-term contract	Day-rate interim	Fractional
Employed by	The agency	You	Own company / umbrella	Own company
On your payroll	No	Yes	No	No
Typical duration	Days to months	3–18 months	2–12 months	Ongoing, part-week
Typical level	Transactional to qualified	Qualified to manager	FC, FD and specialist	FC, FD, Head of Finance
Speed to start	Days	Notice period applies	Days to two weeks	Days to two weeks
Cost basis	Hourly/daily incl. margin	Salary + employment costs	Day rate	Day rate, part-week
Ends by	Ending the booking	Contract expiry	Assignment end	Notice by either side
Key legal point	Agency Workers Regulations	Fixed-term Employees Regulations	IR35 status	IR35 status

What each actually costs

The honest comparison is not headline rate against headline rate, because the arrangements bundle costs differently. An FTC at a £60,000 equivalent salary costs the employer roughly £72,000–£76,000 fully loaded once employer’s National Insurance, pension and holiday are added — about £310–£330 per working day. An agency temp at the same level might charge £350–£420 a day all-in, the premium buying flexibility and speed. A day-rate interim at Financial Controller level runs £400–£600, and at FD level £700–£1,200 — higher per day, but with no employment costs, no notice period, no holiday or sick pay, and no recruitment cost when the need ends. Fractional is priced per day at similar rates to interim but consumed at one or two days a week, so the annual cost is a fraction of a full-time equivalent.

The mistake that costs most is comparing a day rate to a salary rather than to the fully-loaded employment cost, and concluding that interim is expensive. For a defined, time-bounded need it frequently is not — and the calculation should also weigh what the arrangement avoids: a permanent hire made for a temporary need is the most expensive outcome of all.

The legal points that matter

Three areas where getting it wrong has consequences, and where this guide is a starting point rather than advice — for anything specific, take proper employment advice.

Fixed-term employees have real rights. Under the Fixed-term Employees Regulations they must not be treated less favourably than comparable permanent employees on pay, benefits or access to opportunities without objective justification. They accrue continuous service, unfair dismissal protection applies in the usual way, and where an employee has been on successive fixed-term contracts for four or more years, the contract can become permanent unless the continued use of an FTC is objectively justified. Non-renewal of an FTC is a dismissal in law, so the ending needs handling properly rather than being treated as automatic. Acas publishes clear guidance, and gov.uk sets out the statutory position.

Agency workers acquire rights at twelve weeks. Under the Agency Workers Regulations, after twelve weeks in the same role an agency worker becomes entitled to equal treatment on basic working and employment conditions — pay, working time, holiday — as if they had been recruited directly. Businesses that plan a long agency booking should price that step and diarise it rather than discovering it.

IR35 applies to the contractor routes. For medium and large businesses, the responsibility for determining a contractor’s status sits with the engager, and the determination must reflect the actual working arrangement rather than the contract label. A genuine interim working across clients on a defined assignment with their own judgement is frequently outside; someone integrated into the team, directed day to day and doing a permanent role by another name is not. Blanket determinations are a common and costly error — they narrow the candidate pool and push up the rate the remaining contractors require. Our guide to IR35 and employment tax covers the framework, and HMRC’s off-payroll guidance is the primary source.

Which fits which need

Maternity or long-term absence cover at qualified or manager level: usually a fixed-term contract. The duration is known, the work is a defined role, and an employee arrangement suits both sides. At Financial Controller level and above, a day-rate interim is often the better fit, because the candidates who cover FC and FD maternity leave are typically career interims. Our guidance on maternity cover FC recruitment covers that band.

A defined project — a systems implementation, a first consolidation, an audit remediation, an IFRS conversion: day-rate interim almost always. You are buying specific experience for a specific outcome, and someone who has done that exact thing before is worth the premium many times over.

Peak workload or short-term gaps at transactional level: agency temping, which is what it exists for — fast, flexible, and no commitment.

A bridge while a permanent search runs: interim at senior level, agency temp below it. This is also the arrangement most likely to convert — interims frequently become the permanent hire, and it is worth agreeing conversion terms at the outset rather than negotiating them awkwardly later.

An ongoing need that is genuinely part-time: fractional. If you find yourself repeatedly extending an interim assignment, you are describing a fractional need and should structure it as one.

A permanent need: hire permanently. Repeatedly rolling temporary arrangements to avoid a headcount decision costs more, loses the best people to businesses that will commit, and in the FTC case can create the permanence you were trying to avoid.

Making the arrangement work

Whichever route you choose, three practices improve the outcome. Be explicit about the end — the date, the trigger, and what happens if the work finishes early or runs long; ambiguity here is the source of most temporary-arrangement friction. Onboard properly anyway. Businesses routinely under-invest in inducting temporary staff on the basis that they are not staying, then wonder why the first fortnight produced little — for a three-month assignment, a fortnight of drift is a sixth of the engagement. Plan the handover from day one, particularly for interim assignments: documentation, templates and a successor briefing should be deliverables of the engagement rather than an afterthought, as our interim handover guide sets out. The businesses that get most from temporary finance capability treat it as a designed intervention with a defined output, not as a gap being plugged.