Before allowing anyone into your home to carry out gas work you should ask to see his or her CORGI identification card. It will be the size of a credit card and show their photograph, name, CORGI registration number, card expiry date and the CORGI logo. The key information is also provided in Braille. You can also contact CORGI directly to check whether an engineer is genuinely CORGI registered, or to find CORGI registered engineers in your area. In order to issue a gas safety certificate, the engineer has to check: