E
Echo
mate the HMRC only catch you out if you blabber and make it obvious!! they dont have any right under data protection to see what certs are issued as they have customer info on them...!!
I don't think thats true as I seem to remember a story from somewhere (can't remember where) of the HMRC linking up with the scheme providers and have investigated a few companies and found a few installation certificates for work that never went through the books. If I remember right they went through the courts.
This is another reason why I would never certify anybody elses installation.
Also receipts and invoices ect have customer info on them but the data protection act doesn't apply to the HMRC on that front, so I can't see it standing up with the certificates either.