Part 1 of the Principal & Associate Tax series

The BDA template associate contract has been the industry standard for self-employed associate status for two decades. From 2024 onward, HMRC has been increasingly testing actual working practice against the contract, with the PGMOL Supreme Court ruling on Mutuality of Obligation reshaping the analysis. Associates who match the template on paper but not in practice are now at meaningful status-determination risk.

The self-employed status of an associate dentist has been, for two decades, the most stable and most widely accepted self-employed arrangement in any UK profession. The British Dental Association template contract was specifically designed to evidence self-employed status. That position has weakened materially since 2024, with the Supreme Court ruling in HMRC v Professional Game Match Officials Ltd (PGMOL) reshaping the Mutuality of Obligation test, and HMRC quietly tightening the way it tests actual working practice against the contract.

This piece walks the current HMRC status test, the PGMOL implications, the way the BDA template has evolved, and what associate dentists need to evidence today to defend self-employed status. Sister pieces in the principal/associate tax hub cover professional expenses and indemnity insurance tax relief.

The three classic status tests

HMRC tests employment status against three established tests from Ready Mixed Concrete (1968) and subsequent case law: personal service and substitution, control, and Mutuality of Obligation (MOO). A genuine self-employed contractor evidences absence of personal service obligation (with right of substitution), low control (the worker decides hours, methods, sequence), and no MOO (the engager has no obligation to offer work and the worker has no obligation to accept). All three are tested cumulatively.

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Substitution: the dental version

The BDA template grants the associate the right to provide a substitute dentist to perform the contracted work. In practice, substitution in dentistry is restricted: the substitute must be GDC-registered, sufficiently experienced, indemnified, and acceptable to the principal's practice (typically through a formal vetting process). These restrictions do not invalidate the substitution right; courts have repeatedly held that qualification-based restrictions on substitutes are compatible with genuine self-employment.

The fatal weakness: a contract that says "subject to principal approval not unreasonably withheld" without objective qualification criteria. That language is closer to employment than self-employment and is the most common drafting issue in non-BDA-template contracts.

Control in a dental practice

A self-employed associate exercises significant clinical autonomy: they decide treatment plans, sequencing, and how to deliver care within professional standards. The principal does not direct clinical work. This is a strong control argument for self-employment.

Where control weakens: rotas that the associate cannot decline, principal-set surgery hours that the associate must observe, principal-controlled patient appointments, and integration into the practice's wider operations (team meetings, NHS recall systems, performance reviews). The more an associate looks like part of the team rather than an independent practitioner, the more control points away from self-employment.

PGMOL and Mutuality of Obligation in 2026

The Supreme Court ruling in PGMOL (2024) confirmed that MOO can exist within a single engagement, not just across engagements. For associate dentists, the practical implication is that a contract requiring the associate to attend specific sessions and the principal to pay for those sessions creates MOO during the sessions themselves. This narrows the historical self-employed defence for associates on regular weekly sessions; the safer position is contracts that explicitly state no obligation on the principal to offer specific session times and no obligation on the associate to accept.

The BDA template position

Test	BDA template position	Working practice that matches
Substitution	Right to provide qualified substitute	At least one example of offering or using a substitute
Control	Associate decides clinical methods and treatment plans	Practice cannot override clinical decisions
MOO during session	No obligation on either party for specific session attendance	Sessions can be declined or moved by mutual agreement
MOO between engagements	No obligation on principal to offer further sessions	Sessions are agreed period by period, not perpetually
Equipment	Associate provides own loupes, scrubs, handpieces	Documentation of personal purchase
Indemnity	Associate carries own indemnity insurance	Policy in associate's name

What HMRC actually looks for in a status review

HMRC compliance officers reviewing associate status typically focus on: actual substitution evidence (not just contract language), how rotas are set and amended, whether the associate has multiple practice engagements, the level of integration into the practice team, who funds and arranges CPD, whether holiday and sickness arrangements look more employee-like, and the contract itself. A combination of strong contract plus weak working practice is the most common failure pattern.

Practice-side implications

If HMRC recharacterises an associate as employed, the practice (as the engager) carries the PAYE and employer NI liability for the past four years, plus interest and penalties. For a practice with five associates and a typical history, this can be a £200,000-£500,000 exposure. The practical defence is rigorous contract review plus working-practice alignment, ideally with an annual review by a specialist dental accountant.

What associates should evidence

Multiple practice engagements (or active marketing for additional engagements).
At least one documented substitution offer or use.
Personal CPD funding, with no expectation of reimbursement.
Personal purchase of major equipment (loupes, scrubs, indemnity).
Session-by-session or period-by-period engagement rather than permanent rota.
Right to decline specific sessions without consequence.
Separate diary, separate patient list (where practical), separate practitioner identity.

Should I move to a limited company?

Operating through a limited company adds complexity but reinforces self-employment evidence on some tests (the company is genuinely separate). It does not avoid the employment-vs-self-employment tests; HMRC will look through the company to the underlying working practice. For higher-earning associates above £80,000-£100,000 of profit, the Ltd company route also offers genuine tax efficiency through salary-dividend extraction and pension contributions. For lower-earning associates, the admin overhead typically outweighs the tax saving.

What if HMRC opens a status enquiry?

A status enquiry typically begins with a letter asking for the contract, working practice details, and recent self-assessment returns. Response should be coordinated with a specialist dental accountant and possibly a tax solicitor. The 30-day response window is firm; missing it triggers escalation. Cooperation with full documentation is consistently the best strategy; obstruction or partial disclosure compounds risk.