I have had a couple of requests for copies of COC's for as far back as 5 and even some for 7 years back.

Customer I still do work for 15 years later ... I have every document fom the plans to the invoices everything ... however I no longer do work for a customer ... after 5 years the documents get shredded ... included COC's.

So how long is a COC's vaild ?

Taking in consideration the environment for example and office block I wired 11 years ago ... I still do work in the building and the building is still the same as it was 11 years ago.

Lets use a factory as and example where there is continuous maintenance ... additions and alterations going on.

What I am asuming is that either property management company or the insurance company has requested a COC.

This is where the documented the information would come in handy ... ie photos specific details about each circuit ... down to wire size etc.

This is something I should approuch insurance comanies about ... offering to carry out random checks on COC's issued for properties ... including site visits ... to make sure that COC's being used ... do in fact cover the entire building and not just part invoices tentants or property owners use from a single socket outlet which was installed 2 years ago.