£800/day outside IR35: where the Ltd advantage starts shrinking

The scenario

A senior consultant, let's call them Alex, is on a £800/day outside-IR35 contract with a FTSE client. The engagement is genuinely outside (specialist deliverables, substitution clause used at least once, multiple parallel clients over the year). Alex has a Ltd company, an IR35 insurance policy, and a contract review on file. Personal circumstances:

• Resident in England (rUK income tax).
• Under State Pension Age.
• No student loans.
• £12,570 director salary (the standard PA strategy).
• Working 220 days. £800/day × 220 days = £176,000 of annual revenue.
• No pension contributions in this base scenario (the elephant in the room, added as a sensitivity case at the bottom because at this rate it changes the picture meaningfully).

All figures use 2026/27 tax-year rates.

Step 1, Annual revenue

VAT-exclusive. Alex's Ltd is VAT-registered (compulsory above £90k) and uses the Flat Rate Scheme at the 14.5% IT sector rate, which keeps a small VAT margin not modelled here.

Step 2, Director salary, employer NI, operating costs

Same setup as the £500/day scenario, the salary strategy doesn't change just because the day rate is higher. In fact, at very high revenue (£300k+) the salary-vs-dividend optimiser sometimes nudges to a lower £5,000 ST salary because the PA fully tapers, but at £176k the PA only partially tapers, so £12,570 is still the optimum.

Step 3, Pre-tax profit and corporation tax

The effective CT rate is now 24.2%, closer to the 25% main rate than the 22.5% Alex's £500/day counterpart paid. That's already £6,308 more CT for the same company structure, simply because the profit is bigger and sits closer to the top of the marginal-relief band.

Step 4, Distributable as dividends

Step 5, The £100k personal-allowance taper bites

This is where it gets interesting.Alex's total personal income:

That's above £125,140, meaning the personal allowance is fully tapered to zero. Every pound of the £12,570 salary is now taxable at 20% basic-rate income tax, where in the £500/day scenario the same salary attracted £0.

The mechanic of the taper: above £100,000 of total income, the £12,570 personal allowance is reduced by £1 for every £2 of income above the threshold. By £125,140 the entire PA is gone. Alex is well past that.

Step 6, Income tax on salary

With the PA fully tapered, all £12,570 of the director salary is taxable at 20% basic-rate income tax:

That's £2,514 of income tax that the £500/day Ltd director (with full PA) doesn't pay. Already the £12,570 strategy looks slightly less efficient at this rate level, and at very high revenue (£300k+) it would actually be beaten by a £5,000 ST salary, per our salary vs dividend split optimiser.

Step 7, Dividend tax with all three bands

With taxable salary of £12,570 (PA gone), dividend tax calculation starts from there:

All three dividend bands hit. The additional-rate band (39.35%) only takes a small slice, but that's where the Ltd-vs-umbrella gap closes: PAYE's additional rate is 45%, dividend additional is 39.35%, so the differential at the very top is only 5.65pp instead of roughly 15pp at lower rates.

Step 8, Net to pocket

Retention: about 56.5% of revenue. Alex keeps £8,300/month or £1,910/week of personal cash flow.

Why the Ltd advantage shrinks at this rate

At £500/day the Ltd advantage over umbrella is about £3,600/year. At £800/day the gap shrinks to roughly £1,800/year, half. Three things conspire:

1. PA-taper: above £125,140 the personal allowance is gone, so the £12,570 director salary that was tax-free at £500/day is now taxable. The Ltd loses that ~£2,500 of free salary advantage.
2. Additional-rate dividend tax (39.35%): kicks in above £125,140 of total income. PAYE's additional rate (45%) is only 5.65pp higher, so the Ltd-vs-umbrella differential shrinks meaningfully here.
3. Corporation tax rises with profit: in the marginal-relief band, the effective CT rate climbs from 19% (at £50k) to 25% (at £250k). At £160k profit we're at ~24% effective vs ~22.5% for the £500/day contractor, a 1.5pp drag worth £2,400 on Alex's extra profit.

For Ltd contractors at £800+/day, the qualitative case for staying outside-IR35 (admin time, IR35 risk, complexity) starts to outweigh the shrinking financial advantage. Some contractors at this rate level deliberately go umbrella for the simplicity, especially if their engagement has any IR35 risk.

What changes if…

… Alex puts £40,000 into pension via the company?

Employer pension contributions deduct from pre-tax profit (saving CT at the 26.5% marginal rate) and don't count as personal income (so no income tax, no NI, no dividend tax). The £40,000 also keeps total personal income below the PA-taper threshold, so the £12,570 PA is recovered. CT saving alone: ~£10,600. Plus the dividend tax saving on the £40,000 of dividends Alex no longer takes (at the higher/additional band ≈ 35.75%): another ~£14,300. Total tax saving: ~£24,900 on a £40,000 contribution. Effectively £40,000 in pension at a personal cash-flow cost of ~£15,100. The single most impactful tax move available to high-rate Ltd directors.

… Alex goes umbrella instead?

Same £176,000 assignment rate via umbrella nets about £97,800. Difference: ~£1,800/year in favour of Ltd. At lower day rates the Ltd advantage is larger; at higher day rates it compresses; at very high rates it can flip negative briefly. See the inside vs outside IR35 comparison page for the four-rate sensitivity table.

… Alex retains £30,000 in the company?

Skipping £30,000 of dividend extraction this year saves ~£10,725 of dividend tax (most of it at the 35.75% higher rate), that money sits in the company having paid only corporation tax. Distribute it later in a lower-income year and pay the dividend tax then at potentially basic rate. Or wind down the company eventually via Members' Voluntary Liquidation and extract at 10% capital gains with Business Asset Disposal Relief, a saving of about 25-29 percentage points on that £30,000 if eligible. Retained earnings is the single biggest under-used lever for high-rate Ltd contractors.