I am not advocating anything regarding your customers. We are now in a time where everyone expects a COA for everything, even if they don't know why they need a COA or what they are specifically looking for on the COA. It is CYA mode for everyone, which is understandable in this age of lawsuits and litigation.
What I'm communicating is from the receiver of the materials. Do not assume the materials meet the specifications on the COA. From this point of view, in my 20 plus years experience, COA's are pointless. I have come across far too many material supply issues where I had a COA in hand showing everything was within specification.
So, if you are a supplier to a customer requesting a COA you have to determine what works for you and the customers. I've had customers who are fine with a CoC (Certificate of Conformance) or a Letter of Guarantee. Typically, these are customers that do more testing in-house of the materials before receiving, or with pre-ship samples sent to them. I've also had customers who tell me they will not receive material without a COA in hand, but they don't know what they need on the COA; it just has to be a COA. Fine...these customer get something that says "within specification" on a few different things of the material. It does depend on the type of material you supply, and the "critical nature" of the material. I haven't had much success in convincing customers COA's are unnecessary, but I've had some good conversations about them where customers do more of their own testing in house, or they find out, "Hey I need to be testing for this and I didn't even know."
Ryan M. - OK, let's suppose we stop sending our products for micro testing as we're absolutely sure our programs work perfectly and we're safe to sell our products without testing. What do I say to our customers requesting COAs (most of our customers do that)? Make the COAs up?