The A1 certificate (or Portable Document A1, PDA1) confirms that a posted worker remains subject to the social security legislation of the sending country. This avoids double contributions (in both home and host country) and simplifies payroll. For EU postings, the certificate is issued under EU Regulation 883/2004. The employer applies to the social security authority in the sending country before the posting begins. The certificate states the period of validity and the applicable legislation.

For UK-Italy postings (post-Brexit), the UK-Italy bilateral social security agreement applies. A1 certificates are issued by UK authorities. The process and validity periods differ from the EU system. We help you apply for A1 certificates, ensure applications are submitted in time, and advise on renewal when postings are extended. We also assist with PD A1 for EU postings from other member states. Without a valid A1, the worker may become subject to Italian social security (INPS), which can significantly increase costs and administrative burden.