What is wrong with "clients you must refuse"
Sorting clients by health condition and then declaring "you cannot have this" sounds responsible. It fails in two ways.
The first is authority. Deciding whether a health condition rules out a procedure is a medical judgement. What a practitioner can judge is whether this procedure carries uncontrollable risk in their hands — not whether someone's condition permits a service.
The second is accuracy. Blanket rules such as "absolutely not for pregnant clients" or "any keloid tendency is a dealbreaker" are not what the clinical literature supports. And one rule the industry repeats constantly — stop isotretinoin 6–12 months ahead — traces back to small case series from the 1980s.
A workable split has three layers: what the law fixes, what public health requirements fix, and what only a clinician can answer.
Layer one: what the law fixes
There is no judgement call here. In the UK, the Tattooing of Minors Act 1969 makes tattooing anyone under 18 an offence regardless of parental consent, and it is a matter for the police. Age thresholds and exceptions differ by jurisdiction, so cross-border enquiries need checking against both the client's location and the location of the work.
The practical step is to verify age in the booking flow rather than estimating. Whether a record must be kept depends on the requirements of your jurisdiction.
Layer two: what public health requirements fix
The author of the rules on this layer is a regulator or public health body — not the studio, and not ATTO.
The FDA states that unsterile tattooing equipment and needles can transmit infectious disease, including HIV and hepatitis, and records that contaminated inks have caused infections even when the artist followed hygienic procedures. The CDC advises that instruments and materials intended to penetrate the skin, ink included, be used once and disposed of, or cleaned and sterilised before reuse.
In England and Wales, skin-piercing activity requires registration of both the practitioner and the premises under Part VIII of the Local Government (Miscellaneous Provisions) Act 1982, extended to semi-permanent skin colouring by section 120 of the Local Government Act 2003, with local byelaws setting out cleanliness, sterilisation and waste requirements.
So the studio's job on this layer is to meet the requirements of its own jurisdiction rather than execute a checklist from a brand or an article. What a client can check is those requirements themselves: single-use instruments, packaging opened in front of them, pigment documentation available, and premises registered.
Layer three: what only a clinician can answer
This is the layer that matters most: these questions are not the studio's to answer, so the correct action is not to decide but to hand them back.
- Whether a health condition affects healing or immune status.
- What to do about anticoagulant or antiplatelet medication. Any change to medication belongs to the prescriber; a client should not stop medication on their own, and a practitioner should not advise stopping or reducing it.
- Whether to proceed while taking isotretinoin or similar retinoids. The industry's "stop 6–12 months before" rule has no single medical basis — it rests on small case series from the 1980s, and the 2017 systematic review of other skin and laser procedures did not cover tattooing or PMU at all. So this question belongs to the prescribing clinician, not to an article.
- Whether to proceed during pregnancy or breastfeeding. This is a clinical question; what a studio can explain is its scheduling.
- Active skin lesions in the treatment area, and the possibility of the Koebner phenomenon in people with pre-existing skin disease such as psoriasis.
- Keloid tendency. The FDA states that people prone to keloids are at risk of keloid formation from a tattoo, and that keloids may form whenever skin is injured. Assessing whether someone is "prone" is a clinical question.
- A previous reaction to pigment or anaesthetic products. Note in particular: patch testing has poor predictive value for tattoo pigments — the clinical literature describes skin testing for these colorants as producing disappointing results. "Patch tested, no reaction" is not a safety clearance.
- Lip work and a history of herpes simplex. The clinical literature lists herpes simplex infection among the early-onset complications of cosmetic tattooing, most relevant at the lips. Whether to assess for it and whether medication is appropriate are answered by someone who can prescribe.
Handing the question back is the professional move
When a question sits on layer three, the usable sentence is: this step needs a clinician's view. Whether to seek one, and when, is the client's decision.
Three things to keep apart. Do not explain the client's condition, suggest medication, or comment on their doctor — that is both a risk and a reason for the client to treat you as a medical source. Do not turn an open question into a flat prohibition: the correct statement about pregnancy is "this is a question for a clinician", not "pregnant clients cannot". And keep two separate decisions apart: the health question goes to a clinician, while the studio may decline an appointment on its own grounds — capability, insurance cover or a stated policy — subject to applicable local law and anti-discrimination rules.
What to keep on record
The record serves one clear purpose: making later problems traceable. If your jurisdiction sets its own record requirements, follow them. In practice that means the pigment batch and area treated, the client's allergy and adverse-reaction history, and the medication the client reports. These are records, not decision criteria.
The bottom line
Once "should this be done" is split into three layers, the practitioner's position is clear. Legal duties cannot be delegated, public health requirements cannot be skipped, and health conditions sit with clinical care — where the right move is not a refusal, but handing the question to whoever can answer it.