I recently received a contract for a project. One of the many points of contention was the paragraph that said, "The Subcontractor shall proceed with the changed work as directed by the Contractor while such claim for adjustment is being determined as provided in the Subcontract documents."
So, IOW, do the work and hope the Contractor approves the C/O.
Get the C/O signed before doing the work.
I have a residential addition that we are currently working on. While reviewing the kitchen cabinet drawings I notice an electric oven. I didn't remember seeing it on the blueprints. Thinking I had missed it I pulled out the blueprints. Nope, no oven.
So I call the owner and ask, "Are you installing an electric oven ?"
"Yes, it's in the drawings."
"It's not in the blueprints but I see it in the kitchen cabinet drawings. I will draw up a C/O and send it to you to sign."
"Well, it needs to get done so just rough it in and we'll work it out later."
"I think it would be best if we agreed to the C/O before we do the work."
This same owner wants me to fix the mess another electrician created in the Master Bath. The electrical as installed is a wreck. So I give him a proposal for the work and he says, "I don't want to spend that much. Can't we just do the minimum ?"
"If I touch it I have to make it safe."
"But I can't spend that much on the bathroom. I'm already over budget."
Needless to say we haven't done any work in the bathroom. The last time we were on the job he asked if we could go over the work to be done in the master bathroom. I told him, "I explained what needed to be done but you haven't agreed to my proposal."
It's still up in the air.
When I worked for another EC we had one GC who instructed his field superintendant's to sign ALL C/O's without any delay. However, the GC also instructed his superintendan't to add the following words under their signature, "My signature above only verifies that the work was performed." This was used to prevent delays in the job BUT more importantly to give him a way out of paying for the C/O's. I learned later from my employer (who was also my brother) that the GC argued at the final meeting that his superintendant's were not authorized to approve C/O's.
Just another typical GC.