What paperwork should solar panel installers leave with you?

[Deleted User]

Just wondering if there are particular items of paperwork I must have from them?

thenudeone

Absolutely essential
the blue certificate which you will need to register for FITs.
invoice / receipt including name & address (you may need proof of ownership to register for FITs)
Electrical safety certificate (otherwise you will need to get the council to certify compliance with Part P building regs - £££s)
receipt for any extra warranties

Others to consider:
circuit diagram
inverter manual
warranty documentation
panel serial numbers and location plan
product technical specifications / literature (model numbers, dimensions, electrical features etc) for all parts including mounting system