What salary sacrifice actually is
The employee gives up part of their contractual salary and the employer pays the same amount into their pension instead. Because the money never becomes salary, it is not taxed as salary and no National Insurance is due on it — the employee’s or the employer’s. That is the whole mechanism. It is not a loophole and it does not need a scheme number; it needs a contract variation.
In an agency this covers negotiators, valuers, branch managers and lettings administrators. The catch is that a negotiator's pay is mostly commission, and a sacrifice set as a flat monthly amount against a variable income behaves very differently in a quiet quarter.
The Employment Allowance kills the business case more often than anything else
The employer saving is 15% of whatever is sacrificed — but only if you are actually paying employer National Insurance. The Employment Allowance covers the first £10,500 of a qualifying employer’s secondary Class 1 bill, and a smaller payroll can sit entirely underneath it. If it does, the business saves nothing, whatever the sacrifice.
That does not make the scheme pointless. The employee saving is real and it is the larger of the two. It does mean the business case has to be honest about which one you are buying.
What changes in 2029
From 6 April 2029, only the first £2,000 sacrificed by an employee in a year keeps the National Insurance exemption. Anything above that will carry both employer and employee National Insurance as if it had been paid as salary. Income tax relief is not affected. A scheme set up now is not wasted — it has three tax years before the cap bites, and £2,000 a head stays exempt afterwards — but any modelling that runs past 2029 has to include it, and most of what you will read online does not.
Commission is what makes this awkward
Sacrifice is a permanent variation to contractual pay, and the National Minimum Wage floor applies to what is actually paid. A negotiator on a low basic plus commission can clear the floor comfortably in a strong month and breach it in a slow one, with the sacrifice still coming out. Set it as a percentage of pay, or set it against basic only, and review it rather than leaving it running.
The other consequence is that commission-heavy pay makes gross salary look smaller on paper. That matters when a negotiator applies for a mortgage — and estate agents apply for mortgages.
Where it works properly
Branch managers and valuers on a stable salary, and the administration and accounts side, are where an agency scheme actually lands. Model those first and treat the negotiator population separately.
Before the first payroll run
This is a contractual change, so it needs a written variation the employee agrees to, and it has to be prospective — you cannot sacrifice pay already earned. Auto-enrolment duties continue to apply and the sacrificed amount still counts toward the minimum contribution. Get the payroll software set up for it before the first run rather than unpicking it afterwards.