Insights

CMA £500 Written Estimate Rule for Vets, Explained

Last reviewed: 1 October 2026 · Written by Isaac Stevenson BVMSci MRCVS

From 2027, a treatment likely to cost £500 or more must come with a written estimate. This page covers when one is needed, what goes in it, how soon it must be given, and what happens when the cost goes up.

This is a plain-English summary to help practices get their bearings. It is not legal advice, and the Order itself is the authority. The official documents are linked at the foot of this page.

When you need one

Two things must both be true:

the whole treatment pathway is likely to cost £500 or more, including VAT, counting what the owner has already paid in the last three months; and
more than £100 of that has not been spent yet.

So a case that has already cost £480, with only a £40 recheck left, does not need one.

What counts as the treatment pathway

Everything you have recommended to diagnose, treat or manage the condition:

tests and treatment from the previous three months;
what is likely in the next 12 months, including referral;
what goes with it: medicines, anaesthetic, aftercare and follow-up visits;
euthanasia and cremation, where they are likely.

You only estimate what you can reasonably foresee. If you can only see one month ahead, estimate one month.

Take a dog that is drinking more than usual. A consultation at £55 and bloods and urine at £145 would not make anyone reach for a form. Add the follow-up bloods, a scan and a year of medicine, and the plan comes to £710. The written estimate is due when you recommend that plan.

What goes in it

What has been done already: a short summary and one total.
What is still to come: a figure where you are confident, a range where you are not.
A breakdown of the main parts still to come, with tests and treatments shown separately.
What could change it. Only things you are aware of, not remote possibilities.
Referral: your best estimate, and a line telling the owner to confirm the price with the referral centre.

The Order does not publish a template.

How soon

In time for the owner to think it over and get another estimate if they want one. At the latest, by the end of the next working day after you recommend the plan.

The CMA says an estimate handed over on the consent form may be too late.

In an emergency you treat first. The estimate follows as soon as reasonably possible once the emergency is over.

When the cost goes up

You must give a new written estimate if the total is likely to rise by 20%, or by £500, whichever is lower.

On a £600 estimate, that is £120.
On a £1,200 estimate, £240.
On a £4,000 estimate, £500.

Where you gave a range, the top of the range is what is measured. The new estimate must say what has been paid for, what is still to come, and that it replaces the earlier one.

It must be given as soon as reasonably possible. The Order does not say it must arrive before you carry on. With an animal on the table you still speak to the owner and agree what to do, as you would now, and send the written update afterwards.

When you do not need one

The owner has clearly said they do not want a written estimate. The Order does not ask you to record this, but a line in the clinical notes is worth having.
Once the owner has chosen to go to a referral centre, you do not have to send a new estimate when the costs there change.
A long-term condition where 12 months have passed and the plan has not changed.

Keeping records

Keep a copy of every written estimate for 12 months, whether or not the owner went ahead.

When you have to be ready

A large business runs 15 or more practices. Anything below that is small.

Written estimates: 22 June 2027 (large) · 22 September 2027 (small)
Published price lists: 22 December 2026 (large) · 22 March 2027 (small)

The price list comes about six months earlier. That helps, because an estimate is built out of the price list.

From the consulting room

I understand why this is needed. Cost is a big part of how an owner decides what to do, and they cannot decide well without knowing it.

It is going to be tricky, though. Vets will have to find the time to write these, and estimating accurately is hard. A lot of the time, when we start working a case up, we do not know how many steps it will take.

The rule does allow for that. You estimate only what you can reasonably foresee, so the first estimate may cover no more than the first round of tests, and a range is allowed where a single figure would be a guess.

A written estimate also protects the vet. Most arguments about a bill start with an owner who did not expect it.

But it does not replace talking it through. A page of figures handed over without explanation helps nobody.

Five things practices will get wrong

Reading £500 per invoice. It is per treatment pathway.
Adding VAT afterwards. The £500 includes it.
Leaving it to the consent form. By then the owner has usually decided.
Missing the 20% update on mid-sized estimates.
Treating it as an admin job. The threshold is crossed in the consulting room. What the rules ask of the vet in the room.

How Vet Amica helps

When an estimate follows a set of lab results, Vet Amica makes it easier to write.

It turns the lab report into a plain-English summary for the owner: what was found, what it means, and what happens next. Each next step is listed with the price from your own price list beside it. You edit it and approve it, and nothing reaches the owner until you have.

So the costs still to come are already drafted, in writing, next to the reason for each one.

Vet Amica is not a compliance tool, and no regulator approves software of this kind. The duty under the Order, and the estimate itself, remain yours.

Talk to us See how it works

Where to check this yourself

The CMA's guidance for veterinary businesses, and the Order and its Explanatory Note (GOV.UK).

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