UK Contractor Outlook 2027-28: IR35, Thresholds and Autumn Budget Impact

UK contractors have had a rough three years. The 2024 IR35 reform reclassified work on dozens of previously-outside roles. Fiscal drag has quietly raised effective tax rates every year since 2022 as thresholds stay frozen. 2027-28 doesn't look like a reversal — it looks like continuation. Here's what to plan for.

Fiscal drag: still the biggest hit

The personal allowance (£12,570) and higher-rate threshold (£50,270) have been frozen since 2021-22 and are currently scheduled to stay frozen through 2027-28. For a contractor earning a flat day rate, this means more of each pay rise crosses into the 40% band every year. On a £500 day rate (~£110K revenue outside IR35), the effective tax rate rose roughly 1.5 percentage points between 2023-24 and 2026-27 purely from fiscal drag. 2027-28 adds roughly 0.5 more points on current forecasts.

What the Autumn Budget 2026 is likely to change

At the time of writing (October 2026) the 28 October Autumn Budget hasn't landed. Market and industry forecasts flag three plausible changes:

• Dividend tax rates up by 1-2 percentage points (8.75→10%, 33.75→35%). Hits outside-IR35 limited company contractors directly, as this is their main income path.
• National Insurance thresholds held or lowered. A frozen primary threshold at £12,570 for another year means fiscal drag continues; a reduction would raise effective tax immediately.
• Corporation tax changes unlikely but possible — the small-profits rate (19% up to £50K) is politically sticky.

We'll update this post with the actual Budget outcome and specific numbers once announced.

IR35 enforcement in 2027-28

The April 2024 off-payroll working reform remains the status quo. HMRC's CEST tool keeps producing inside-IR35 outcomes on contracts that would have been outside under the pre-2017 rules. Private-sector hirers continue to default to inside-IR35 for liability-management reasons, independent of how the work looks. Expect this pattern to continue through 2027-28; the Chancellor has not signalled any reversal.

The dividend tax question

Dividend tax is the single most politically-exposed tax rate for limited company contractors. Current rates (2026-27): 8.75% basic, 33.75% higher, 39.35% additional, with a £500 allowance. A 1-point rise would cost a typical outside-IR35 contractor on a £500 day rate around £800/year in extra tax. A 2-point rise, around £1,600/year. Watch for this in the Autumn Budget.

Pension sacrifice remains the strongest lever

Across both inside and outside IR35 scenarios, pension contributions remain the most tax-efficient income lever available to UK contractors in 2027-28. Inside IR35 via salary sacrifice: saves marginal income tax + both employee and employer NI. Outside IR35 via company contribution: tax-deductible for the company (saves corporation tax at 19-25%) and no personal income tax hit. The annual allowance remains £60,000 for most contractors, with carry-forward of unused allowance from the previous three tax years.

Tip: Model your own 2027-28 take-home with the UK IR35 Take-Home Calculator. Rates will be updated within 48 hours of the Autumn Budget announcement.

What to watch after the Budget

The 48 hours after the Budget are when the Treasury red book clarifies the detail that was glossed over on the day. For contractors, the three items to extract are:

• Any change to income tax thresholds (personal allowance, higher rate, additional rate).
• Any change to NIC thresholds (primary, secondary, upper earnings limit).
• Any change to dividend tax rates or the dividend allowance.
• Any announcement on the small-profits corporation tax rate or the taper band.

If none of these move, 2027-28 looks structurally identical to 2026-27 — just worse by fiscal drag. If any move, re-model your take-home before setting your 2027-28 day rate.