IR35 AccountantsHMRC IR35 Enquiry Defence
Specialist response to HMRC employment status enquiries and compliance checks: first-letter strategy, evidence, settlement arithmetic and honest advice on when to concede or fight.
HMRC can assess 4 years back, 6 if careless, 20 if deliberate · Penalties 0% with reasonable care, up to 30% careless
HMRC IR35 Enquiry Defence: what you need to know
An IR35 enquiry rarely announces itself as one. The opening letter usually reads as a routine employer compliance check, asking how your engagements are structured, how status was decided and for copies of contracts. What you send back in those first weeks shapes the entire enquiry, because every statement becomes part of the record and casual answers create openings that take years to close. The single most valuable move is getting specialist eyes on the letter before anything is returned.
Defence work is part evidence, part arithmetic. The evidence side assembles contracts, working-practice statements, substitution records and the contemporaneous status reviews that demonstrate reasonable care. The arithmetic side matters just as much: which assessment window applies, four years for innocent error against six for carelessness, is usually worth more than any single status argument, and since April 2024 the offset rules mean tax already paid on the same income reduces what HMRC can demand. We run both tracks from the first response.
Honest defence also means honest advice about settling. The sound approach costs both routes: total exposure across the open years with penalties and interest, against realistic tribunal prospects on your actual contracts and practices. Penalties alone can swing from 0% with reasonable care to 30% for carelessness and beyond for deliberate behaviour, so how the case is argued changes the bill even when the status point is lost. We give you that costed picture early, then fight or settle accordingly.
What you get
First response handled by a professional
The opening letter is answered accurately and narrowly, giving HMRC what it asked for and nothing speculative, which is where most self-inflicted damage is avoided.
Years and penalties argued down
Holding the assessment window at four years and the penalty at nil through reasonable-care evidence often saves more than the status argument itself.
Offset rules applied in full
Since April 2024 corporation tax and dividend tax already paid on the disputed income reduce the PAYE demand, and a specialist makes sure every credit is claimed.
Fight-or-settle advice with numbers
You get both routes costed against tribunal prospects on your facts, not bravado in either direction.
What's covered under hmrc ir35 enquiry defence
We handle the full range of work that sits within hmrc ir35 enquiry defence, including:
IR35 compliance check response
Professional handling of HMRC's opening employment status letter, scoping what must be disclosed and drafting the reply before the deadline.
Status defence evidence assembly
Contracts, working-practice statements, substitution records and client confirmations organised into the file the enquiry will be argued from.
Discovery and time limit challenges
Arguments on which assessment window applies, since the difference between four and six years is frequently the largest number in the case.
Penalty mitigation and behaviour arguments
Building the reasonable-care case that holds penalties at 0%, and managing disclosure quality and cooperation where some penalty is unavoidable.
Settlement calculations and offset claims
Independent checking of HMRC's figures, applying the April 2024 set-off rules so tax already paid on the same income is credited in full.
Tribunal and ADR referral
Where a case should be fought, we prepare it for alternative dispute resolution or the First-tier Tribunal and bring in counsel as needed.
Who this is for
We are engaged by contractors including:
- A contractor holding an unanswered HMRC letter about employment status with a response deadline two weeks away.
- A PSC director whose former client is under an off-payroll compliance review and whose engagements are being examined as part of it.
- A contractor mid-enquiry who answered the first letters alone, said too much, and now needs the position professionally recovered.
- A director facing a carelessness argument that would stretch the assessment window from four years to six, roughly doubling the money at stake.
- A contractor weighing a settlement offer who wants the figure independently checked, including the post-2024 offsets, before signing anything.
How an engagement works
Tell us what HMRC has sent
The letter type, the deadline and a sketch of the engagements under question. Urgent deadlines are flagged at this stage.
Fixed written quote in 48 hours
We come back with a fixed written quote for the immediate stage, fast-tracked when HMRC's clock is already running.
Priced stage by stage
Enquiries unfold in phases, so each stage is quoted as a fixed fee before it starts, then re-quoted if the case develops.
We take over the correspondence
HMRC deals with your representative from then on, with you briefed at each step.
Read before you decide
The guides library covers the rules behind this service in depth.