Is it safe to paste NHS numbers or health information into ChatGPT?
An NHS number should never go into ChatGPT, and nor should health details that point to a named person. Health information is special category data under UK GDPR. A public AI tool is not a safe place for it. You can still use AI for health-related work, but only once names, NHS numbers and other identifiers are taken out, and only on a business account your firm has approved.
Why an NHS number in ChatGPT is a problem
An NHS number is not just a reference. It is unique to one person for life. According to the NHS Data Dictionary, it is 10 digits long. The tenth digit is a check digit, worked out with a sum called Modulus 11.
That makes it easy to spot. It also means anything next to it is linked to a real person. A sick note summary with an NHS number on it is health data about someone you can identify.
The NHS itself is cautious here. One trust's policy, from Rotherham Doncaster and South Humber NHS Foundation Trust, says ChatGPT must not be used for patient-identifiable information. The same policy notes NHS England guidance that sensitive patient information must not go into generative or publicly available AI tools. UKMi guidance for NHS staff goes further: patient identifiable information must never be entered into AI systems.
If clinicians are held to that line, an HR team or care agency should not set a lower one.
Health data is special category data
UK GDPR treats some data as more sensitive. Health is one of them. So is data on ethnicity, religion and sex life.
The ICO explains the effect. To use health information lawfully, you need two things. First, a lawful basis under Article 6. Second, a separate condition under Article 9.
Having a reason to hold sickness records does not cover sending them to a new tool. Each new use needs its own thought.
What that means for AI use
Pasting health data into an AI tool is a new use. The provider becomes part of the chain. You need to know where the data goes, who can see it and whether it is kept.
The ICO also says you are more likely to need a DPIA for special category data. A DPIA is a Data Protection Impact Assessment: a written check of the risks before you start. In some high-risk cases it is required.
For most small firms, the simple path is to keep identifiable health data out of AI altogether. For the wider picture, see our plain-English guide to UK GDPR and AI tools.
Rule of thumb: if a reader could work out whose health it is, it stays out of AI. Take the person out first. Then the question can go.
Yes, no or only if: common tasks
Here is how this works for everyday tasks in HR, care and occupational health. The verdicts assume a firm has no special agreement in place for health data.
| Task | Verdict |
|---|---|
| Pasting a fit note with name and NHS number | No |
| Summarising an occupational health report about a named worker | No |
| Uploading a care rota with residents' conditions | No |
| Drafting a return-to-work letter, with "Employee A" in place of the name and no diagnosis | Only if details are taken out |
| Asking how to apply a sickness absence policy to a general scenario | Yes |
| Explaining a medical term in plain English | Yes |
| Writing a template for absence reviews | Yes |
| Analysing sickness figures by team | Only if names and conditions are removed and teams are large |
The pattern is simple. General questions are fine. Templates are fine. Anything about a real, identifiable person is not.
Why small groups still count
Removing a name is not always enough. "The only warehouse manager in Leeds, off with a back injury" points to one person. Watch job titles, rare conditions and small teams. Dates can give someone away too.
The rules a small firm should set
Write these down. Keep them short. Staff follow one page better than ten.
- No identifiers. No NHS numbers, names, dates of birth or addresses in any AI tool.
- No diagnoses tied to people. Conditions can be discussed in general, never about a named worker or client.
- Stand-ins only. Use "Employee A" or "Resident B" when drafting.
- Approved accounts only. Business accounts the firm has checked, not personal free accounts.
- A human checks. AI output on health matters is reviewed before it is used or sent.
- Ask first. Unsure? Ask the data protection lead before pasting.
An AI policy template for UK employees can hold these rules. Our post on how to redact before pasting covers the taking-out step in detail.
Does a business AI plan change the answer?
It helps, but it does not remove the rules. Some business plans offer a data processing agreement and keep data out of training. That covers part of the risk. You still need your Article 9 condition. You may still need a DPIA. Note that the trust policy above treats Microsoft Copilot differently from public tools. That reflects NHS arrangements, not a general green light.
Where rules meet real life
Rules on paper do not stop a rushed paste on a Friday afternoon. Take Ashcombe, a fictional care agency. Priya is writing up a client's needs. She pastes the care plan into ChatGPT to tidy it. The NHS number goes with it.
A check before sending catches this. Helio Guard does it on each Windows PC, in Chrome and Edge. It spots NHS numbers using the check digit, and other items such as National Insurance numbers. It can take them out and swap in a label, so the question still goes. Client names can become a stand-in such as "Client A". Checked on the PC, with fixed rules. We never see what your team types.
It does not judge whether a sentence describes someone's health. A diagnosis written in words still needs your rules and training. Windows only for now. It costs £1 a person a month, from 5 people, with a 14-day free trial and no card needed. The pricing page has the details.
Common questions about health data and AI
Can I put an anonymised health report into ChatGPT?
A truly anonymised health report can go into ChatGPT, because anonymous data is outside UK GDPR. The catch is that true anonymity is hard. Removing the name and NHS number may not be enough if job title, location, dates or a rare condition still point to one person. If in doubt, treat the report as identifiable.
Is pasting an NHS number into ChatGPT a data breach?
Pasting an NHS number into ChatGPT can count as a personal data breach if it was not authorised and puts the person's data at risk. Whether it must be reported to the ICO depends on the risk to that person. Record the incident, assess it promptly and speak to your data protection lead the same day.
Can occupational health providers use AI at all?
Occupational health providers can use AI for general work, such as drafting templates, explaining terms or planning workload. Anything about a named worker needs a lawful basis, an Article 9 condition and usually a DPIA before AI is involved. Many providers keep identifiable records out of AI entirely and use it only for general tasks.