At/upon request

[Allen165]

"At request, XXX shall assist in the search of the cause of malfunction."

"At the Customer's request, XXX shall perform its services for a separate fee outside the standby time as well."

I'd like to know if "at" should be replaced with "upon." I don't think it should, but I'm not sure.

Thanks!

 

[bhaisahab]

"At request, XXX shall assist in the search of the cause of malfunction."

"At the Customer's request, XXX shall perform its services for a separate fee outside the standby time as well."

I'd like to know if "at" should be replaced with "upon." I don't think it should, but I'm not sure.

Thanks!

I would replace "at" with "upon" in the first one, also, I would change "of the cause" to "for the cause" and put "the" before "malfunction".
I would rewrite the second one as "At the customers request, XXX shall perform its services outside the standby time for a separate/supplementary/an extra fee".