The 22–23% Rule: Why It's Consistent Across Day Rates
When a contract moves from outside IR35 to inside IR35, contractors consistently need a 22–23% rate increase to maintain the same net income. This holds whether you're billing £300/day or £800/day, because the tax differential is roughly proportional to earnings at every level.
Two things drive the gap:
- Employer National Insurance (15%). Inside IR35, your gross pay is subject to employer NI before you even see it. This is deducted from the fee the client pays — reducing your deemed payment before income tax and employee NI are calculated. Outside IR35, your limited company pays a much smaller employer NI bill (only on a small salary), and the rest comes out as dividends with no NI at all.
- Loss of the dividend tax advantage. Outside IR35, you extract most of your income as dividends taxed at 8.75% (basic rate) or 33.75% (higher rate). Inside IR35, the same income is taxed as employment income at 20% and 40% — a substantially higher rate. You also lose the ability to time your dividend payments to minimise your tax band exposure.
These two factors compound: employer NI shrinks your gross before it reaches you, and then what does reach you is taxed more heavily. The result is a consistent ~22–23% penalty regardless of where you sit on the rate spectrum.
Framing matters. When you ask a client for £615/day instead of £500/day, you are not asking for more money. You are asking for the same take-home pay after the government takes a different — and larger — slice. The client's total cost may not change much, because they no longer pay your Ltd company's corporation tax indirectly through the rate.
Rate Uplift Table: £300–£800/Day
The table below shows what you'd need to charge inside IR35 to match your outside-IR35 take-home, based on 220 working days per year, England tax rates, and the 2025/26 tax year. The final column shows what agencies typically offer in practice.
| Day Rate (Outside) | Take-Home Outside (Ltd) | Equivalent Inside IR35 Rate | Uplift | Agencies Actually Offer |
|---|---|---|---|---|
| £300/day | ~£49,800 | £370/day | +23% | £310–£320 |
| £400/day | ~£63,500 | £490/day | +23% | £420–£440 |
| £500/day | ~£79,500 | £615/day | +23% | £525–£550 |
| £600/day | ~£94,000 | £735/day | +22% | £630–£660 |
| £700/day | ~£107,500 | £855/day | +22% | £735–£770 |
| £800/day | ~£120,000 | £975/day | +22% | £840–£880 |
Figures are illustrative for 2025/26, 220 days/year, England & Wales. Actual take-home depends on expenses, pension contributions, and personal allowance usage. Use our IR35 calculator for your exact number.
At £300/day, the shortfall between what you need (£370) and what agencies offer (£315 midpoint) is about £55/day — roughly £12,100/year. At £700/day, the shortfall between £855 needed and £753 offered is £102/day — roughly £22,440/year. The percentage gap is similar, but the absolute cost of accepting an inside IR35 role without full uplift increases dramatically at higher rates.
The Real-World Gap: What Agencies Actually Pay
The table above tells one story. The market tells another. In practice, agencies offer a 3–10% uplift when a role shifts inside IR35 — nowhere near the 22–23% needed to break even.
Why the gap? Several factors work against full uplift:
- Client budgets are fixed. Most hiring managers have a total-cost-to-company budget approved before IR35 status is even determined. They cannot add 22% to the budget after the fact.
- Agencies absorb margin pressure. The agency margin often shrinks on inside-IR35 contracts because employer NI comes out of the same pot. They pass some of that pain through to you rather than absorbing it all.
- The "compliance premium" framing. Many agencies frame the small uplift as a goodwill gesture — "we're giving you a bit more because it's inside IR35." In reality, the economics still leave you significantly worse off.
- Supply and demand. If there are enough contractors willing to accept inside IR35 roles at lower rates, the market clears at those lower rates regardless of what the maths says you need.
The result: most contractors moving inside IR35 take an effective 12–18% pay cut once you account for the partial uplift they receive versus the full uplift they need.
A £50/day shortfall sounds manageable. But over 220 days, that's £11,000 per year — after tax. Many contractors find it easier to assess the real cost when they convert the daily gap into an annual figure.
How to Negotiate Your Inside IR35 Rate
You won't always get full uplift, but you can do better than the default agency offer. Here's a practical approach:
- Lead with numbers, not emotion. Prepare a one-page breakdown showing your outside IR35 take-home versus the inside IR35 take-home at the offered rate. Make it undeniable. Agencies and clients respond to spreadsheets, not complaints.
- Show the client the take-home comparison. Many hiring managers genuinely don't understand the tax mechanics. When you show them that £500/day outside and £500/day inside produce wildly different net outcomes, they often have more flexibility than the initial offer suggests.
- Frame the uplift as compliance cost. Position the rate increase as the cost of HMRC compliance, not a personal pay rise. The client was already paying your Ltd company rate — the government is just taking more of it now. The total cost to the client may not change much once you factor in that they no longer risk IR35 liability themselves.
- Consider partial uplift plus other benefits. If full rate uplift is off the table, negotiate on other fronts: employer pension contributions (which come out of the gross before tax, reducing the sting), training budgets, longer notice periods, or guaranteed contract extensions. A 15% uplift plus 5% employer pension contribution gets you closer to break-even than 10% uplift alone.
- Know your walk-away number. Before you start negotiating, calculate the minimum rate at which the contract still makes financial sense for you. Factor in bench time between contracts, the certainty of income, and career value. If the offer falls below your floor, be prepared to walk.
When to Walk Away from an Inside IR35 Role
Not every inside IR35 contract is worth taking. Here's a simple framework:
- If the gap between the offered rate and the break-even rate exceeds 10%, the maths probably don't work. At £500/day outside, you need £615 inside. If they're offering £540, that's a 12% shortfall — you're losing roughly £16,500/year in take-home. That's a significant pay cut to accept voluntarily.
- Factor in contract length. A 3-month inside IR35 contract at a lower rate might be worthwhile if it fills a gap between better-paying outside IR35 work. A 12-month contract at the same rate locks you into a year of reduced income.
- Consider bench time. If you've been on the bench for two months and the inside IR35 offer is the best available, the lost income from continued bench time may exceed the rate shortfall. Two months at zero versus ten months at a 10% shortfall is an easy calculation.
- Assess career value. Some contracts offer experience, client relationships, or CV credentials that justify a temporary pay cut. A high-profile digital transformation at a FTSE 100 inside IR35 may open doors that a better-paying but obscure outside IR35 contract wouldn't.
Calculate your annual take-home at the offered inside IR35 rate. If it's within £5,000 of what you'd earn outside IR35, it's probably worth considering. If the gap exceeds £15,000, you need a strong non-financial reason to accept.
April 2026 Impact: Does the Uplift Change?
The short answer: the uplift percentage stays broadly similar in 2026/27. The personal allowance remains frozen at £12,570, the higher rate threshold stays at £50,270, and National Insurance rates are unchanged. This means the same 22–23% rule of thumb holds.
What does change is the small company threshold. From April 2026, the thresholds for qualifying as a "small company" under the Companies Act increase significantly. This means more of your clients will qualify as small companies — and for small company engagements, IR35 status determination responsibility shifts back to the contractor.
In practical terms, some contracts that were inside IR35 under the off-payroll rules (because the client was medium/large and made a blanket determination) may effectively move back to outside IR35 if the client now qualifies as small. This won't change the uplift calculation, but it may change which of your contracts need uplift at all.
For the full detail on how the threshold changes affect contractors, see our April 2026 small company threshold changes guide.