Umbrella vs PSC vs Fixed-Term for Interim Finance Work

Every interim finance assignment has to be structured somehow, and the structure determines how you are paid, what protections you have, and what the arrangement is worth. Most people encounter the question for the first time when an offer arrives and a recruiter asks whether they operate through a limited company — which is a poor moment to be working it out. This guide explains the three structures used in UK interim finance, what each means in practice for both sides, and how IR35 status changes the answer. It is a general explanation for finance professionals and employers, not tax advice: your own position depends on facts this guide cannot know, and it is worth an hour with an accountant before you decide.

The three structures

Personal service company (PSC). You form and run your own limited company, contract through it, and draw income as a mix of salary and dividends. You are a director and shareholder of your own business, with the administrative obligations that implies: accounts, corporation tax, VAT if registered, insurance. Standard at Financial Controller, Finance Director and specialist level, where assignments are longer and rates justify the overhead.

Umbrella company. You are employed by an umbrella company, which contracts with the agency or client and pays you through PAYE after deducting its margin and employment costs. No company to run, no accounts to file, and you get statutory employment rights through the umbrella. Common where assignments are short, where the client has determined the role is inside IR35, or where someone does not want the administration.

Fixed-term contract (FTC). You are employed directly by the client for a defined period. On payroll, PAYE, holiday accrual, pension auto-enrolment, and the protections that come with employment — including the right not to be treated less favourably than comparable permanent employees — the statutory position is on gov.uk with practical guidance from Acas. Most common up to Finance Manager level, where the candidate pool genuinely includes people who will accept employment.

How they compare

Where IR35 changes everything

The structure question cannot be separated from status, because status determines what the PSC route is actually worth.

Where an assignment is outside IR35, income can be taken through your company as a mix of salary and dividends, and the arrangement is generally more tax-efficient than employment. Where it is inside IR35, income is taxed broadly as employment income and the advantage over an equivalent salary narrows considerably — frequently to the point where a fixed-term contract at a comparable rate is the better arrangement once holiday, pension and sick pay are counted.

Two practical points. For medium and large clients the engager determines the status, not you, and the determination must reflect the actual working arrangement rather than the contract wording. And blanket inside-IR35 determinations are common in risk-averse organisations — which is why the same nominal day rate can be worth quite different amounts depending on who is engaging you. HMRC’s off-payroll guidance is the primary source and our guide to IR35 and employment tax covers the framework.

The practical consequence for candidates: ask about status before you discuss the rate, because an inside-IR35 assignment at £500 a day is not comparable to an outside-IR35 assignment at the same number.

Which suits which situation

PSC suits the established interim with a genuine portfolio of clients, working on assignments likely to fall outside IR35 — defined scope, own judgement, not integrated as an employee — where the rate justifies running a company. This is the standard arrangement at FC and FD level.

Umbrella suits shorter assignments, inside-IR35 roles where the PSC advantage disappears, and people trying interim work for the first time who do not want to form a company before they know whether it suits them. It is also the pragmatic answer when a client will only engage through one.

Fixed-term suits maternity and long-term absence cover, roles up to about Finance Manager level, and anyone who values employment protection and benefits over rate. It is genuinely the better arrangement more often than the interim market admits — our guide to temporary, fixed-term and interim arrangements works through the employer’s side of the same decision.

What each is actually worth

The comparison people make — day rate against salary — is the wrong one. Work it through properly.

A £450 day rate at 210 billable days is £94,500 gross. From that, deduct no holiday pay, no sick pay, no employer pension, no bonus, and (through a PSC) accountancy and insurance costs of £1,000–£2,000. Against a £70,000 salary, whose fully loaded employment cost is roughly £84,000 including employer’s National Insurance and pension, and which is paid across all 52 weeks regardless of utilisation.

On those numbers the interim route is ahead — but the gap is smaller than the headline suggests, and it reverses entirely below about 160 billable days. The rate is compensation for carrying utilisation risk, not free money. Rates by role are in our interim finance rate card, and the wider comparison in contracting versus permanent in finance.

Practical points for candidates

Get an accountant before you start, not after. The set-up decisions — company or umbrella, VAT registration, salary and dividend split — are easier made once than corrected later.

Take professional indemnity insurance. Most clients require it, and the cost is modest against the exposure.

Compare umbrellas on the margin and the take-home illustration, and be wary of any arrangement promising unusually high retention — schemes of that kind have caused a great deal of difficulty for contractors in other sectors.

Read the engagement letter properly, particularly notice, scope and any restriction on working for competing clients.

And plan the pension deliberately. It is the single most neglected part of interim working, and the one where the gap against employment compounds fastest — MoneyHelper covers the options for the self-employed.

Practical points for employers

Assess status before you advertise, not at offer stage. Candidates will ask, and a determination made late looks like an afterthought.

Understand what a blanket determination costs. Deciding everything is inside IR35 feels safe, but it narrows the pool and raises the rate the remaining contractors require — frequently costing more than the risk it avoids.

Be flexible on structure where you can. Insisting on one route removes candidates who work through another for good reasons.

And remember the FTC option at manager level. Unlike at FC and FD, plenty of capable Finance Managers will take a twelve-month contract — a wider pool at a lower cost, covered in our guide to interim Finance Manager cover.