Understanding UDA Values and NHS Orthodontic Contracts in 2026

If you run an NHS orthodontic contract, or are thinking of taking one on, the first thing to know is a point of terminology that catches many practice owners out: orthodontic activity is counted in Units of Orthodontic Activity (UOAs), not Units of Dental Activity (UDAs). UDAs measure general dental services such as examinations, fillings and extractions. UOAs measure orthodontic assessments and courses of treatment. People search for "UDA orthodontics UK 2026" because the two terms are used loosely, but the contract mechanics, the claim form and the performance management are different. This guide explains how NHS orthodontic contract units work in England, what the "value" of a unit really means, and which numbers a practice should track every month to stay on the right side of its contract.

UDA and UOA: what is the difference?

A UDA is a unit used to measure general dental activity under an NHS dental contract; a UOA is the equivalent unit for orthodontic activity. Both systems came from the contract reforms introduced in England in April 2006, under the National Health Service (General Dental Services Contracts) Regulations 2005 and the matching Personal Dental Services arrangements. Under those arrangements, a contract holder agrees to deliver a number of units and is paid an annual contract value in return, rather than being paid item by item.

The practical consequence is that advice written for general dental contracts, including much of what is published about UDA values and clawback, cannot simply be copied across. The unit weightings, the claim timing and the patient pathway are specific to orthodontics. The exact UOA weightings for assessments, appliance placement and completed treatment are set out in the national regulations and NHS Business Services Authority (NHS BSA) guidance, and they are worth reading directly rather than relying on a second-hand summary.

How does an NHS orthodontic contract work?

An NHS orthodontic contract fixes three numbers: an annual contract value, an annual UOA target, and the contract term. Divide the first by the second and you have the contract's value per UOA, sometimes called the UDA value in loose usage. Two practices doing identical clinical work can have very different values per unit, because contract values were set from historical baselines and not from a single national price.

Commissioning has also moved. From 1 April 2023, responsibility for commissioning NHS dental services in England was delegated from NHS England to integrated care boards (ICBs), so your day-to-day contact for contract variation, activity queries and funding is now usually your local ICB or the regional NHS England team acting for it. New or re-procured NHS healthcare contracts are awarded under the Provider Selection Regime, which has applied since 1 January 2024, rather than the older public procurement rules.

What is the value of a UOA, and why does it vary?

The value of a unit is the contract value divided by the contracted units, and it is not a national tariff. That is the single most misunderstood point. A practice cannot look up "the UOA rate" because there is no single rate. The figure that matters is the one in your own contract, and it is the lens through which you should judge whether a particular case, an extra clinic session or an extra associate is worth taking on for NHS work.

Suppose a hypothetical contract is worth £600,000 a year for 6,000 UOAs. The value per unit is £100. If the practice delivers 5,700 UOAs, that is 95 percent of target. Depending on the tolerance applicable to that contract, the unfilled units could expose the practice to recovery of the funding attached to the shortfall. If the practice delivers 6,000 units with the same clinical team, the same overheads and the same contract income, the margin on every extra case in the year comes from using capacity fully, not from a higher price.

Which numbers should an NHS orthodontic practice track?

The most useful management numbers are units delivered against a monthly profile, completions waiting to be claimed, and treatment duration against plan. A year-end reconciliation is far too late to correct a shortfall, because orthodontic treatment takes 12 to 24 months for most fixed appliance cases, so the units you can deliver this year are largely determined by the cases you started and managed in the previous 18 months.

Our guide to orthodontic practice KPIs covers the wider dashboard, and using practice analytics to grow shows how to move from monthly spreadsheets to a live view.

Why does patient eligibility matter so much to contract performance?

NHS orthodontic treatment is funded only where there is a clinical need, assessed with the Index of Orthodontic Treatment Need, so every assessment slot used on a patient who will not qualify is capacity that does not generate units. The IOTN grades dental health from 1 to 5, and the NHS normally funds treatment for patients at the higher grades, with grade 3 cases decided using the aesthetic component. If you are unfamiliar with how the scoring works, see our explainer on what an IOTN score is, and the public IOTN score checker that patients can use to understand their likely outcome.

Handled well, the private pathway is not a lost patient but a second route. Patients who do not qualify need a clear, kind explanation and a transparent private quote, and they are far more likely to take it if they have already seen the options. Our article on NHS waiting lists and private orthodontics sets out the patient's side of that conversation.

How should a practice protect unit delivery through the year?

Build a monthly delivery profile

Take the annual target, adjust for the months you expect to be quieter (school holidays and summer leave tend to affect child attendance), and chart actual units against that profile every month. A profile turns a vague worry into a number and a date.

Close the loop on claims

Every course of treatment generates paperwork, and every missed or rejected FP17O is delivered work that does not count. Allocate one named person to check claim status weekly, and make it part of the debond or completion checklist so claims are submitted the same week.

Manage the waiting list actively

Waiting lists are both an asset and a risk. A healthy list guarantees starts, but a list nobody reviews drifts, with patients who have moved, lost interest or been treated elsewhere still counting as demand. Regular contact keeps the list accurate, and our guide to orthodontic waiting list management sets out a practical routine.

Reduce preventable attrition

Patients who stop attending leave treatment half finished, which means units that cannot be completed. Reminders, clear expectations at consent and flexible appointment times all help. For the private side of the same problem, see orthodontic patient dropout.

What should you check before bidding for or renewing a contract?

Contract rules and commissioning arrangements change, sometimes at short notice, so treat any summary, including this one, as a starting point and confirm the current position with your commissioner, NHS BSA and your professional body. The British Orthodontic Society publishes information for members on commissioning and contract matters.