hamil,
Now I understand. When you said “certificate” I was thinking you were asking about a separate rating since the FAA doesn’t actually issue a license, they certify that you met some standard on a certain date. Everyplace I know it’s more about hiring the person. The TC, whether it’s attached to an airline or a stand alone company, will run you through their program to get you familiar with it. Then you’ll do some supervised instruction and finally be signed off and added to that TC's instructor list