Replacing an employee is commonly estimated at 6–9 months' salary once hiring, onboarding and lost productivity are counted. Health cover at the ~£57/head/month average costs less than half a 3% rise on a £35,000 salary, and surveys consistently rank health cover as the most-valued voluntary benefit — but cash still wins where pay is below market. Most firms need both.
- ✓Replacing an employee is commonly estimated at 6–9 months' salary all-in.
- ✓Health cover at ~£57/head/month costs roughly half a 3% rise on a £35,000 salary.
- ✓Health cover is the most-valued voluntary benefit — but it can't fix below-market pay.
What losing someone actually costs
Start with the number that frames everything: replacing an employee is commonly estimated at somewhere between 6 and 9 months of their salary — some studies land lower for junior roles and considerably higher for senior or specialist ones, so treat it as a hedged range rather than a law. The components add up fast: recruitment fees or advertising, management time interviewing, onboarding and training, the months a new hire takes to reach full productivity, and the output lost while the seat is empty.
That asymmetry is why retention spend is cheap relative to churn: anything that measurably reduces departures competes against a very expensive alternative. And churn compounds — each departure loads work onto the colleagues who stayed, which is how one resignation becomes two. The question is whether benefits or cash reduces departures better per pound spent.
£57 a month vs a 3% rise: the head-to-head
Put the two options side by side for a £35,000 employee. A 3% rise costs the employer £1,050 in salary plus employer NIC on top — call it roughly £1,200 a year. Health cover at the ~£57/head average costs £684 in premium plus Class 1A NIC at 15% on the benefit — about £790 a year — and generally attracts corporation tax relief, like salary.
| 3% pay rise (£35k salary) | Health cover (~£57/head/mo) | |
|---|---|---|
| Employer cost/year (incl. NIC) | ~£1,200 | ~£790 |
| What the employee sees | ~£58/month extra take-home (basic rate) | Full private cover; BIK tax ~£11/month |
| Salience after 12 months | Absorbed into normal — rarely remembered | Re-felt at every GP call, claim and family illness |
| Value if bought personally | — | Individual cover averages ~£80/month — ~£960/year |
Two things stand out. The employer pays a third less for the benefit than for the rise. And the perceived value runs the other way: the employee's £58 a month extra take-home disappears into the current account, while the benefit delivers something they'd pay ~£960 a year for personally — group rates typically run 10–30% below individual pricing — for a benefit-in-kind tax cost of around £11 a month at basic rate.
Why benefits punch above their cost
The behavioural case rests on salience. Pay rises suffer from fast adaptation: within months, the new salary is simply the salary, and its retention effect fades. A health benefit re-announces itself every time it's used — the GP appointment within hours, the physio sorted in a week, the scan that would have meant a 12.4-week median NHS wait handled in days. Each use is a small, vivid reminder of what the employer provides.
The survey evidence points the same way: health cover consistently ranks as the most-valued voluntary benefit in UK employee research, and yet only around 31.5% of employers offer it — meaning it still differentiates in a way a market-rate salary can't. There's also a hard-edged retention mechanic worth naming honestly: an employee mid-way through treatment, or whose family is covered, faces a real cost to leaving for an employer without cover — switching may mean new underwriting and losing cover for conditions that have since become pre-existing.
Run the numbers for your team
When cash still wins
An honest comparison has to give cash its wins, because there are several:
- Below-market pay. If salaries lag the market, fix that first. A candidate comparing a £3,000 salary gap against health cover will take the £3,000 — and existing staff run the same maths.
- Lower earners and squeezed budgets. For employees managing tight household finances, £58 a month of real cash beats a benefit they may hope never to use. Forcing benefits on people who need cash reads as tone-deaf.
- Universality. Everyone values cash identically; a young, healthy employee may genuinely value PMI at less than its cost (though digital GP and mental-health access narrow that gap).
- Simplicity. A rise involves no scheme admin, no benefit-in-kind reporting, no renewal negotiations.
The pattern in practice: cash wins the recruitment headline and corrects under-payment; benefits win the years-long retention grind once pay is broadly fair. Which is why the real answer is rarely either/or.
The combined strategy
Most firms that get this right run both, sequenced sensibly: pay at or near market rate as the foundation, then benefits as the differentiator — because moving pay from market-rate to market-rate-plus-5% is expensive and invisible, while adding the most-valued voluntary benefit costs less and is highly visible. In a year where budgets force a choice, one credible pattern is a slightly smaller rise plus the introduction of health cover, communicated as a package: "2.5% plus private health cover" routinely beats "3%" on total value and lands better, provided the pay foundation is sound.
Whatever mix you choose, communicate the total: employees consistently underestimate what benefits cost their employer, so an annual total-reward statement — salary, pension, health cover with its real market value — makes the invisible spend visible. For where health cover fits in a wider package, see our £50-a-head benefits strategy and full benefits stack costs; for the hiring-side version of this argument, see competing with big-company benefits.
Frequently asked questions
Is it cheaper to offer health insurance than a pay rise?
Usually, yes. Health cover at the ~£57/head/month UK average costs an employer about £790 a year including Class 1A NIC — versus roughly £1,200 for a 3% rise on a £35,000 salary once employer NIC is added. Both generally attract corporation tax relief, so the gap holds after tax.
How much does it cost to replace an employee who leaves?
Common estimates land around 6–9 months' salary once recruitment fees, management time, onboarding and lost productivity are counted — roughly £17,500–£26,000 for a £35,000 employee, more for senior or specialist roles. It's a hedged range, but even the low end dwarfs the annual cost of health cover.
Do employees value health insurance more than a pay rise?
It depends on the employee, but survey evidence consistently ranks health cover as the most-valued voluntary benefit, and its value is re-felt at every use — unlike a rise, which is psychologically absorbed within months. Where pay is below market or budgets are tight at home, though, cash still wins.
Does offering health benefits actually improve staff retention?
The evidence supports a real effect: health cover tops most-valued-benefit surveys, only around 31.5% of employers offer it, and employees mid-treatment or with covered families face genuine switching costs in leaving. But it amplifies a fair deal rather than rescuing a poor one — underpaid or badly managed people leave anyway.
What does £57 a month health cover give an employee compared to £57 of salary?
As salary, £57 a month becomes roughly £38 of take-home for a basic-rate employee. As health cover, it buys private cover that would cost around £80 a month individually — group rates run 10–30% cheaper — for a benefit-in-kind tax cost of about £11 a month. On pure value transferred, the benefit wins clearly.
When is a pay rise better than health benefits for retention?
When pay is below market — no benefit offsets a £3,000 salary gap; when your workforce skews toward lower earners for whom cash relieves real pressure; and when you can't resource scheme admin and comms. Fix pay to market level first; benefits differentiate best on top of a fair salary.
Can I give a smaller pay rise and add health insurance instead?
It's a credible package if pay is already fair: "2.5% plus private health cover" typically costs similar or less than 3% and delivers more total value, since cover would cost employees ~£80/month personally. Communicate it as a package with the numbers shown, and expect it to land badly if salaries lag the market.
How do I explain the value of health benefits to employees?
Show the arithmetic: what the employer pays (~£57/month), what equivalent personal cover costs (~£80/month), and what the employee's benefit-in-kind tax is (~£11/month at basic rate) — then remind people quarterly what the cover does. An annual total-reward statement makes the invisible spend visible.
Is health insurance or salary more tax-efficient for the employer?
They're closer than often claimed: both generally attract corporation tax relief, salary carries employer NIC at standard rates while the benefit carries Class 1A NIC at 15%, and the employee pays income tax either way (on the benefit value rather than the cash). The bigger difference is the group-rate discount and salience, not tax magic.