Insurance Curator 
If your business relies on a single star performer—the sales director with the golden Rolodex, the technical wizard who knows every line of code, or the founder whose name is linked to your brand—you already understand the risk. Losing them could cripple operations, tank revenue, and leave partners scrambling. That’s where key person insurance comes in.
But how much cover do you actually need? Valuing a key person isn’t guesswork. In this guide, we’ll break down the three main methods—revenue contribution, profit impact, and replacement cost—so you can set a defensible sum assured. Whether you run a London-based tech startup or a family firm in Manchester, getting the number right protects your company’s future.
Understand how the wealthy use life insurance as a tax-free savings tool—perfect context for key person strategies.
Why an Accurate Valuation Matters
Overinsuring wastes premium. Underinsuring leaves your business exposed. A well-calculated policy ensures you have enough cash to find and train a replacement, cover lost profits during the transition, and reassure lenders or shareholders.
The UK tax treatment of premiums and payouts also depends on the valuation method you use. HMRC often scrutinises key person policies, especially if the sum assured seems arbitrary. A clear, documented calculation strengthens your case for corporation tax relief on premiums.
The Three Main Approaches to Valuing a Key Person
1. Revenue Contribution Method
This method looks at the income the key person directly generates or influences. It’s ideal for sales leaders, business development managers, or rainmaking partners.
How to calculate:
- Identify total revenue attributable to the person (direct sales, contracts won, key accounts managed).
- Estimate the loss period—how long will it take to replace them? Typically 1–3 years.
- Multiply annual revenue contribution by the number of years needed to recover.
Example: A senior broker in Birmingham brings in £500,000 of annual commission. Replacement and ramp-up will take 18 months. Cover needed: £750,000.
Pros: Simple, links directly to top-line impact.
Cons: Doesn’t account for profit margins or wider business costs.
2. Profit Contribution Method
This approach goes deeper. Instead of gross revenue, you calculate the net profit the key person generates. It’s better for technical or operational roles where margins matter.
How to calculate:
- Work out the profit margin on work managed or performed by the individual.
- Multiply by the time needed to stabilise operations (often 2–3 years).
- Add any additional costs (e.g., hiring interim staff, overtime for others).
Example: A software lead in Leeds manages a team that produces £400,000 profit annually. Replacement and retraining take two years. Cover needed: £800,000.
Pros: Reflects true financial impact. HMRC-friendly for tax treatment.
Cons: Requires detailed profit attribution.
3. Replacement Cost Method
Here, you focus on the hard costs of finding, hiring, and training a successor. It’s the most conservative method and works well for roles that are replaceable but not instantly.
How to calculate:
- Recruitment fees (typically 20–30% of annual salary).
- Sign-on bonuses or relocation costs.
- Training and onboarding expenses (often 6–12 months of salary).
- Lost productivity during the learning curve (30–50% of first-year output lost).
Example: A finance director in Glasgow earns £100,000. Recruitment cost £25,000, training £50,000, lost productivity £40,000. Total: £115,000.
Pros: Easy to defend with receipts.
Cons: Ignores lost revenue/profit.
Comparison Table
| Method | Best For | Typical Multiple | Key Inputs |
|---|---|---|---|
| Revenue Contribution | Sales, BD, partners | 1–3x annual revenue tied to person | Direct revenue, recovery time |
| Profit Contribution | Technical, operations | 2–3x net profit from person | Profit margin, stabilisation period |
| Replacement Cost | Admin, support, junior roles | Direct costs only | Recruitment, training, productivity loss |
Which Method Should You Use?
In practice, most UK businesses use a hybrid approach. For example:
- Small firms often rely on revenue contribution because the owner-manager drives almost all sales.
- Professional practices (law firms, accountancies) lean on profit contribution, as billable hours are clearly attributable.
- Corporates with deep pockets may combine replacement cost with a multiple of profit to cover both cash outlay and lost earnings.
If you’re unsure, speak to a financial adviser who understands Key Person Insurance in the UK: How It Works and Which Staff You Should Protect. They can help you model different scenarios.
UK-Specific Factors to Consider
Tax treatment of premiums: Premiums paid on key person life insurance may qualify for corporation tax relief if the policy is taken out solely for business purposes and the sum assured is reasonable. HMRC looks favourably on policies calculated using profit or replacement cost methods.
Payout taxation: If the policy is written in trust, the payout is usually free from inheritance tax. If not written in trust, the proceeds may be liable, reducing the net amount received.
Coverage for loan protection: Many directors use key person policies to guarantee business loans. The valuation should cover the outstanding debt plus interest. Learn more in Using Life Insurance to Protect Business Loans and Director Guarantees.
Relevant life policies vs. key person: For directors, a Life Insurance for Limited Company Directors: Relevant Life Policies and Their Advantages can be more tax-efficient than standard key person cover. Compare both options.
Common Pitfalls to Avoid
- Relying on a single method without justification. Document your assumptions.
- Ignoring the time value of money. Losses in year one are worth more than losses in year three.
- Forgetting shareholder protection. If the key person is also a shareholder, consider a separate Shareholder Protection Insurance Explained: Keeping Ownership Stable After a Death policy.
Practical Steps to Set Your Sum Assured
- Gather data: Three years of financial accounts, client contracts, and role impact notes.
- Choose your primary method (and a secondary as a sanity check).
- Factor in inflation and wage growth. A replacement may cost 5–10% more today.
- Review annually. As the business grows, the key person’s value changes.
- Write the policy in trust to avoid inheritance tax on the payout.
For a deep dive into protecting your business structure, read Funding a Buy-sell Agreement with Life Insurance: Protecting Remaining Shareholders.
Final Thoughts: Get the Cover Right
Valuing a key person is part science, part judgement. The three methods—revenue, profit, and replacement cost—give you a framework, but real-world business risks demand a bespoke number. Over-insuring wastes money; under-insuring gambles with your company’s future.
Start with the profit contribution method for most senior roles, then cross-check with replacement costs. If you’re a start-up, explore Key Person Cover for Start-ups: Lean Strategies That Still Shield the Business.
And if you want to understand how life insurance fits into your overall wealth strategy, pick up a copy of Money. Wealth. Life Insurance.—it’s a classic for a reason.
A clear guide for every stage of life and business.
Ultimately, the right valuation protects your team, your lenders, and your legacy. Whether you’re protecting a key salesperson in Edinburgh or a technical lead in Bristol, take the time to calculate properly. Your business depends on it.