Can I use AD-Vantage Marketing's mailing permit? Yes! We encourage the free use of our mailing permit as a service to our customers whenever we are processing the mailing in your behalf. This will save you $250 in USPS application fees. However, when using our permit, we ask that you "cover us" with an estimated amount of postage and we will adjust to the actual amount on your invoice. Postage deposit checks should be made out to AD-Vantage Marketing.