Sorry,but I have double checked this. The NHS covid site states clearly, "If you order a covid pass letter via NHS 119, or online, the barcode printed on your letter will expire after 30 days". The printed letter does not of itself show any expiry date, only the barcode which forms a part of the letter. Mine will expire a few days before we are off to Jersey, so will need to renew.I applied for a written copy of my vaccinations (and one for the wife) and they arrived 3 days later ! No expiry date whatsoever. Just needed my NHS number (which is on any prescription you may have) and answer a few questions I think. (DOB etc.)