An HMRC investigation into your IR35 status can cost tens of thousands of pounds in professional fees — even if you win. IR35 insurance exists to cover those costs, and in some cases the tax liability too. Here’s what you need to know before deciding whether to buy it.
What IR35 Actually Exposes You To
If HMRC opens an IR35 compliance check on your company, the process can take months or years and involve:
- Detailed questionnaires about your working practices
- Interviews with you and potentially your clients
- Accountant and solicitor time to prepare responses
- Employment tribunal or First Tier Tribunal if you appeal a decision
Professional fees alone: £15,000–£50,000 even for investigations that result in no additional tax.
If HMRC wins, you could also face:
- Back-tax (Income Tax + NI) for up to 6 years (20 years for deliberate non-compliance)
- Interest on unpaid tax
- Penalties (up to 100% of unpaid tax in serious cases)
For a contractor at £400/day earning £80,000/year who was assessed as inside IR35 for 3 years, the total liability could exceed £60,000–£80,000.
Types of IR35 Insurance
1. Investigation Cover Only (Professional Fees)
| Item | Detail |
|---|---|
| What it covers | Accountant fees, legal fees, adviser costs defending the investigation |
| What it does NOT cover | The actual tax owed if HMRC wins |
| Typical annual cost | £200–£500/year |
| Who it suits | Lower-risk contractors; those with robust IR35 status documentation |
Most basic policies through contractor accountants and professional bodies fall into this category.
2. Full Cover (Investigation + Tax Liability)
| Item | Detail |
|---|---|
| What it covers | Professional fees + actual tax/NI/interest liability |
| Liability cap | Usually £50,000–£500,000 depending on policy |
| Typical annual cost | £500–£1,500/year |
| Who it suits | Higher-earning contractors; longer-running outside-IR35 arrangements |
Full cover policies typically require you to have had a formal IR35 status assessment from a qualified tax adviser before the contract started. Without this, the insurer may reject a claim.
3. Group Cover via Professional Bodies / Accountants
Many contractor-specialist accountants include basic IR35 investigation cover in their annual package. Professional bodies (PCG/IPSE) also offer cover to members.
| Provider type | Annual cover | Typical cost |
|---|---|---|
| Accountant package inclusion | £50,000 investigation defence | Included in £1,800–£2,500 accountant fee |
| IPSE membership | Investigation + limited liability | £20–£35/month (varies by tier) |
| Specialist insurers (Qdos, Kingsbridge, Hiscox) | Bespoke | £200–£1,500/year |
What Affects Your Premium
| Factor | Effect on premium |
|---|---|
| Day rate / annual contract value | Higher earnings = higher premium |
| Years in business / contracting | More years = more historic risk to insure |
| Sector | Public sector clients = higher risk (off-payroll reforms stricter) |
| IR35 status determination | Formal assessment reduces premium |
| Previous investigations | Previous investigation = significantly higher premium |
The Formal IR35 Status Determination — Why It Matters
Before buying IR35 insurance (particularly full cover), most insurers require — or strongly prefer — that you have a formal IR35 status determination from a qualified tax adviser. This is separate from HMRC’s free CEST tool.
A qualified IR35 review typically costs £200–£500 per contract and involves:
- Reviewing the contract wording
- Reviewing your actual working practices
- Providing a written opinion on IR35 status
- Recommending contract amendments if needed
Key providers: Qdos, IR35 Shield, WTT Consulting, your contractor-specialist accountant.
Why this matters for insurance: If you’ve never had a formal review and HMRC wins, your insurer may argue you failed to take reasonable care — potentially voiding a claim on a full-cover policy.
Should You Buy IR35 Insurance?
Yes, IR35 insurance is likely worthwhile if:
- You work outside IR35 on contracts paying £300+/day
- You have multiple outside-IR35 contracts over several years
- Your clients include public sector or large private sector end-clients (who have stricter IR35 duties under the 2021 reforms)
- You want peace of mind during HMRC’s current increased compliance activity
It may not be necessary if:
- All your contracts are inside IR35 (umbrella handles the risk)
- You are genuinely self-employed with full substitution rights and no control from clients
- You are earning below ~£40,000/year from contracting (the risk/reward calculation shifts)
- Your accountant’s package already includes basic investigation cover
Cost vs Risk Summary
| Scenario | Likely IR35 risk | Insurance recommendation |
|---|---|---|
| IT contractor, outside IR35, £400/day, 200 days/year | Medium–High | Full cover recommended |
| Management consultant, outside IR35, £500/day | High | Full cover essential |
| All inside IR35 via umbrella | Low (umbrella takes risk) | Not required |
| Locum doctor / NHS worker | High (public sector) | Full cover recommended |
| Freelance copywriter, one client | Low | Investigation-only cover |