Are the calculators HMRC compliant?

Our calculations are built to align with HMRC guidance and use the latest April 2026 rates. However, they're for guidance only – always verify complex cases with HMRC or a qualified professional.

Yes. We're ICO registered (ZC013807) and calculations run in your browser – we don't store sensitive payroll data unless you explicitly save it to your account.

Do you integrate with payroll software?

MBridge tools work as standalone calculators alongside your existing software like Sage, Xero, and QuickBooks. No integration required – use our tools as a pre-check layer.

What's the VAT registration threshold?

The UK VAT registration threshold is £95,000 taxable turnover in a rolling 12-month period. You must register within 30 days of exceeding this threshold.

IR35 (off-payroll working rules) determines whether a contractor working through an intermediary — typically a Personal Service Company (PSC) — should be taxed as an employee. If your engagement is "inside IR35", the fee-payer must deduct Income Tax and National Insurance at source, as if you were employed.

Who decides IR35 status in 2026?

Since April 2021, medium and large private-sector clients (and all public-sector clients) are responsible for issuing a Status Determination Statement (SDS). For small private-sector clients only, the contractor's own intermediary still decides. A client is "small" if it meets two of three criteria: turnover ≤ £10.2m, balance sheet ≤ £5.1m, ≤ 50 employees.

What are the consequences of being inside IR35?

Inside IR35, the fee-payer deducts Income Tax and employee NI from your fees before payment. You lose access to the lower dividend tax rates and corporation tax efficiency of operating via a limited company. HMRC estimates contractors inside IR35 typically take home 15–25% less than equivalent outside-IR35 engagements.

What IR35 changes apply for 2026-27?

There are no structural IR35 rule changes for 2026-27. However, HMRC has significantly increased its enforcement activity and compliance campaigns targeting the tech, financial services, and public sectors. HMRC's CEST tool remains the official determination tool, though it has known limitations — our checker assesses all six HMRC status factors.

What is the substitution test?

Substitution is one of the strongest outside-IR35 indicators. If you have an unconditional right to send a suitably skilled substitute in your place — and the client must accept that substitute — this points strongly to self-employment. The right must be genuine, not a contractual fiction; HMRC will look at working practice as well as the contract.

Can I appeal an inside IR35 determination?

Yes. If a client issues an SDS determining you are inside IR35, you have the right to raise a formal disagreement. The client must respond within 45 days with either a revised determination or written reasons for maintaining the original one. If unresolved, the dispute can be escalated to HMRC's ADR process or the First-tier Tribunal.

Updated for 2026/27

Free IR35 Status Checker 2026/27

Instantly check whether your contract is inside or outside IR35. Our IR35 calculator assesses all six HMRC status factors and gives you a clear determination — no jargon, no guesswork.

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What is IR35?

IR35 — formally the off-payroll working rules — was introduced to tackle "disguised employment": contractors who perform work equivalent to that of an employee but structure their engagement through an intermediary to pay less tax. The rules apply to both the public sector (since 2017) and medium and large private-sector clients (since April 2021).

If your engagement falls inside IR35, you are treated as a deemed employee for tax purposes. The fee-payer must deduct Income Tax and National Insurance before paying your PSC, and you cannot draw the remainder as dividends at the lower dividend tax rates. The typical take-home reduction is 15–25% compared to a genuine outside-IR35 engagement.

Getting it wrong is costly. HMRC can raise assessments for up to six years and charge penalties of up to 100% of unpaid tax where errors are deliberate.

IR35 in 2026-27: What You Need to Know

There are no structural changes to the IR35 rules for 2026-27 — the reformed off-payroll framework introduced in April 2021 remains in place. However, HMRC has significantly stepped up enforcement:

HMRC compliance campaigns are actively targeting the tech, finance, and defence sectors.
HMRC's CEST tool has been updated but still doesn't reach a determination in all cases — approximately 21% of results are 'unable to determine'.
Status Determination Statements (SDS) must now include reasons; blanket assessments remain legally invalid.
Supply chain liability can pass upstream if the fee-payer cannot demonstrate reasonable care in issuing an SDS.

How Our IR35 Checker Works

Our IR35 status check assesses all six HMRC factors. Answer a short set of questions about your engagement and receive an instant inside/outside IR35 determination with a weighted factor breakdown.

Control

Does the client dictate how, when, and where you work? High control is an inside IR35 indicator.

Substitution

Can you send a qualified substitute without client approval? A genuine right to substitute points outside IR35.

Equipment

Do you supply your own tools and equipment? Using client-supplied kit is an inside IR35 indicator.

Financial Risk

Are you exposed to financial risk — correcting defects at your own cost, unpaid downtime? Risk points outside IR35.

Part of Organisation

Are you embedded in the client's structure, managed alongside employees? Integration is an inside IR35 indicator.

Exclusivity

Are you free to work for multiple clients simultaneously? Exclusivity obligations suggest employment.

IR35 Frequently Asked Questions

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Free for your first check. Contractor and Accountant plans include unlimited determinations, PDF reports, and contract risk flagging.

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