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 a dental practice this reaches nurses, hygienists, treatment coordinators and reception. It does not reach self-employed associates, who are not employees and fund their own pensions through self assessment.
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.
The NHS pension is the thing that stops this
Anyone in the NHS Pension Scheme cannot pay their member contributions by salary sacrifice. It is a statutory scheme and contributions are set on pensionable pay, so there is nothing to sacrifice into. That rules out the headline version of this arrangement for most of the clinical side.
Two things still follow from that. Sacrifice for other benefits — a car, cycle to work, additional voluntary contributions into a separate registered scheme — is available, but it reduces pensionable pay, so an NHS scheme member is trading pension for the saving rather than adding to it. And staff who are not in the NHS scheme, which on most sites is a real part of the payroll, can use an ordinary workplace scheme in the normal way.
Work out who is in which scheme before you model anything. The answer is usually a split payroll, not a single scheme across everyone.
Associates are outside this entirely
A self-employed associate has no employment contract with the practice and no salary to sacrifice. Their pension funding is a personal contribution relieved through self assessment. If your associates are in fact being treated as employees, the salary sacrifice question is the least of it.
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.