Healthcare & Medical · US & UK

Can a hospital charge me for something I was not told about beforehand?

Surprise medical bills used to be treated as an unavoidable part of getting care. Recent law in both countries makes that a lot less true.

Kibbo Consumer Desk · Updated September 2026 · 6 min read

It's much harder for them to than it used to be, in both countries. In the US, the No Surprises Act, in effect since January 2022, requires providers to give uninsured or self-pay patients a written Good Faith Estimate of expected costs before non-emergency care. If your actual bill comes in $400 or more above that estimate, you have the right to formally dispute it. In the UK, private clinics operate under Competition and Markets Authority rules requiring clear, upfront pricing information before you agree to treatment — and NHS care remains free at the point of use in any case, so an unexpected charge there would be unusual to begin with.

What the law says

United States United Kingdom
Legal basis No Surprises Act (effective January 2022) NHS care is free at point of use; private care is governed by the CMA's Private Healthcare Market Investigation Order
What providers must disclose A written Good Faith Estimate of expected charges for uninsured/self-pay patients, covering the primary service plus reasonably related costs (tests, equipment, hospital fees) Clear, accurate cost information before treatment, including any additional fees that might apply — CMA rules specifically target hidden or unclear private healthcare pricing
Timeline for the estimate Within 3 business days of a request, or a set number of days after scheduling, depending on how far in advance the appointment is booked No fixed statutory number of days, but pricing must be clear and provided before you consent to treatment
What you can do if the bill exceeds the estimate Dispute the bill through the No Surprises Act's independent dispute resolution process if it's $400 or more above the Good Faith Estimate Challenge the charge as a breach of the CMA order and/or as an unfair contract term if it wasn't disclosed before you agreed to treatment
Insured patients Separately protected against surprise out-of-network billing for emergency care and certain situations at in-network facilities Not typically relevant — NHS treatment doesn't involve billing in this way for the vast majority of care

Worth noting: the Good Faith Estimate requirement in the US currently applies fully to uninsured and self-pay patients. The equivalent protection for insured patients — an "advanced explanation of benefits" showing what you'd owe before treatment — has been the subject of ongoing regulatory work and hasn't been fully implemented in the same way, so insured patients should check what protections currently apply to their specific situation.

Where this actually goes wrong

No estimate was ever given at all

If you asked for a cost estimate before care and never received one, and the eventual bill is a genuine surprise, that alone is worth raising as a Good Faith Estimate compliance issue in the US.

The final bill is dramatically higher than the estimate

A gap of $400 or more between the estimate and the final bill isn't something to simply accept — it's specifically the threshold the dispute process exists for.

An "additional fee" appears that was never mentioned

In the UK, this is precisely what the CMA's cost-transparency rules for private healthcare were designed to prevent — a charge that wasn't part of any pricing you were shown or agreed to beforehand is worth challenging directly.

What to say

Disputing a US bill that exceeds the Good Faith Estimate:

"My final bill of [amount] is more than $400 above the Good Faith Estimate I received of [amount] on [date]. I'd like to initiate the dispute resolution process under the No Surprises Act."

Challenging an undisclosed charge at a UK private clinic:

"I wasn't given clear pricing information for this charge before I agreed to treatment. Can you confirm when and how this was disclosed to me, in line with the CMA's private healthcare pricing rules?"

If it isn't resolved

  1. Request the original estimate or pricing documentation in writing if you don't already have it.
  2. In the US, initiate the formal dispute within 120 days of receiving the bill if it's $400+ above the Good Faith Estimate — this involves a modest administrative fee.
  3. In the UK, raise the issue with the clinic directly citing the CMA order, and escalate to Trading Standards or the CMA itself if unresolved.
  4. Keep every piece of written communication and documentation — estimates, invoices, and correspondence — as this is exactly what any dispute process will require.

Related questions

Official sources

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