Yep, took about 2.5 years (probs covid) to get the official authentication. You have to ship the artwork to a handler, then they ship it to 'Pest Control', Banksy's official team. They do their stuff, then ship it back to the handler who ships it back to you. Then Pest Control send the authentication to the handler who send it to you. A proper ball ache. I saved myself well over £100 dealing directly with the handlers based near Heathrow.