Proof you paid social insurance / social security / superannuation abroad since April 2020 (or since you left the UK, if later). If you worked back and forth, get it from every country you worked in. Sample statements: USA, Ireland, Australia, Italy, Spain, France, Germany, South Africa, Canada
In Ireland: Log in to MyWelfare.ie and request a 'PRSI Contributions Statement'. You'll get an email in approx. 24 hours. Download it and reply to our 'Welcome to XtraPension' email with it attached.
No MyWelfare account? Call 0818 690 690 (option 4) with your PPSN and ask them to post a PRSI statement (1 week). Then send us a clear, non-blurred scan.