IR35 for fractional executives

Outside IR35 by default — and the three tests that keep it that way.

Every Fractional Quest engagement is structured outside IR35 from day one. This guide explains how — and what you (as the engager) need to do to keep it that way. This is a guide, not legal advice.

Default position
Outside IR35by contract pattern
CEST tested
Every engagementHMRC tool on file
Substitution right
Genuinecontractor can substitute
Direction & control
Contractor-leddeliverable not process

The three tests.

IR35 is the UK tax legislation that determines whether a contractor is genuinely self-employed (outside IR35, taxed as a business) or a disguised employee (inside IR35, taxed as PAYE). Three tests dominate the assessment.

Test 1 — Right of substitution

A genuinely self-employed contractor must be able to send a qualified substitute to deliver the engagement.

Not "we'd need to discuss it" — a genuine, unfettered right to substitute.

Every Fractional Quest contract carries this right explicitly, and our fractional CXO network supports it (e.g. a fractional CFO who needs to substitute a Series-B fundraise mandate can draw on the network for cover).

Test 2 — Control over how the work is done

The engager (you) specifies WHAT — the contractor specifies HOW. Outside IR35 means the contractor controls working hours, working location, and methodology.

They're not on your timesheet, they're not reporting to a line manager, they're not subject to your internal HR processes.

Inside IR35 looks like an employee in everything but the contract.

Test 3 — Mutuality of obligation (MOO)

No obligation on you to offer ongoing work, no obligation on the contractor to accept it. An engagement is scoped to specific deliverables and a defined timeframe — when the mandate ends, the relationship ends.

There's no presumption of continuing employment, no notice period, no severance.

What we put in every contract

Substitution clause, control clause, scope-of-work with named deliverables, fixed engagement period, no notice obligation, contractor invoices via their limited company. Plus a CEST test result on file at signing.

The contract pattern has been reviewed by employment-law specialists.

What you (the engager) need to do

Issue a Status Determination Statement (SDS) if you're a medium/large business (or a public-sector body of any size).

Don't put the fractional executive on your internal HR system.

Don't require them to attend daily standups they didn't agree to.

Don't pay for a substitute via your payroll.

If the day-to-day shape of the engagement starts to look like employment, the IR35 outside-status is at risk regardless of what the contract says.

HMRC opens an enquiry, you provide the CEST result + contract + SDS + evidence of how the engagement actually operated. If the practical reality matches the contract — substitution rights respected, contractor controlling working hours, scoped deliverables — the outside status holds. If the engagement looks like disguised employment in practice, HMRC may reclassify and demand back-tax. The contract pattern is necessary but not sufficient; the operational reality matters too.
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