They should be able to get it done anywhere, the obstacle is booking an appointment.
“All sites are reminded that any patient, including NHS staff, does not require a NHS number or GP registration to receive a vaccination and should never be denied one on this basis...If GP registration is not possible, and no existing NHS number can be found, then providers should vaccinate now, record locally via a paper system and ensure that that the vaccination event is recorded on Pinnacle at later date.” (
link)
If it’s easy for them to turn up and ask, I’d suggesting doing that, provided they are age-eligible. Could also ring round the local GPs and ask.