Hi @TrishMcGlynn,
Welcome to the Dyson Community and congratulations on your new Dyson Airstrait™ straightener!
Sorry to hear you’re having difficulty registering your machine, but we should be able to help you with this. For UK Dyson Airstrait™ machines, the serial number is on a sticker/tag attached to the power cable. The format is as follows: AB1-UK-ABC1234A
If you’re confident you’re using the right number but haven’t been successful in registering, it sounds as if your machine is so new the serial hasn’t been added to the system yet. In this case, you’ll need to speak directly to the Dyson UK Customer Care team, who will be able to register your machine for you.
The quickest way to get in touch is to visit Dyson.co.uk and click the round purple button to launch the Dyson Digital Assistant. Then click the agent icon in the bottom left corner of the chat window to start a live chat conversation.
If you’d prefer, you can call our UK Helpline on 0800 298 0298 (available from 8am-8pm Mon-Fri, and 8am-6pm on weekends).
Hope this helps!