HMRC are aware that some customers holding a Frontier Worker permit have been unable to apply for an A1 certificate online and apologise for any inconvenience caused.
We updated the CA8421 application form on 11 November and it can now be used by all Frontier Worker Permit holders.
Following a recent process change, frontier workers seeking to apply for, or renew, an S1 certificate need to apply for an A1 certificate using form
CA8421.
They will automatically receive an S1 certificate (for themselves) alongside their A1 certificate if they are eligible.
The CA8421 does not issue S1 certificates for dependent family members. If any dependents of the individual require S1 healthcare certificates, customers should apply for these using form
CA8454.
Thank you.