My new boiler will be fitted tomorrow. I know the installers print off an invoice in their van, so I'm guessing if all seems well, I pay it there and then. Does the benchmark certificate need to be registered anywhere, or does the engineer fill it in and I get is straight away. Also, should I get the warranty to register myself or does engineer do it? He also, mentioned about having to register the installation with GasSafe, something to do with confirming it has been done in accordance with Building Regs. Do I get notification of this?