Because trademarks in the United States are based on the prior right of use, first use is more important than first registration. However, when applying, you also need to present a proof of use in the United States. If there is no proof of use, then you must declare how you will use it after registration and the proof of use in the United States after applying and before registration. Supporting documents. To express the goods you sell and your intention to use them, the owner of a special trademark should apply for registration.