This brief note is not legal advice and is for educational purposes only.
At the time that you file a trademark (mark) application it can be based on:
More details - "actual use in commerce"
So what does “actual use in commerce” mean? In simple terms it means actual use in “interstate” or “foreign” (outside US) commerce. For goods the mark should be on the goods (e.g. tags, labels, etc.) and for service marks the marks should be used in sales, advertising, etc.
More details - "date of first use" vs. "date of first use in commerce"
“date of first use” is use anywhere, intrastate, interstate, foreign, etc. It may coincide with the “date of first use in commerce” but is generally earlier because of press releases, etc. before actual shipment/performance of goods/services.
“date of first use in commerce” is when you first did interstate or foreign (outside US) commerce. It cannot be earlier than the date of first use but can coincide with it.
Specimens of actual use in commerce are somewhat different based on whether your trademark application was for goods or services. What the USPTO (US Patent and Trademark Office) is looking for is how you use the mark in commerce and how the end-user/customer perceives the mark because the mark is intended to indicate the source of the goods/services.
Services by being non-physical in nature versus physical goods shipped cannot have a physical identification on them and so your services mark would be shown by such things as commercial use in sales, marketing, advertising, leaflets, brochures, etc. Business cards may be acceptable if the mark is next to the service offered. Proofs for ads or news articles about services are not acceptable specimens because they do not show “your” use in commerce.
Goods should show the mark in actual use. For example a tag or label showing the mark affixed to the goods, or its packaging. A drawing of your mark is not acceptable as it does not show “your” use in commerce.
Generally NOT okay for specimens: press releases, mock-ups, prototypes, ornamental use of the mark, invoices, bills of lading, order forms, letterhead, business cards, announcements – forget it because it does not show actual use in commerce.
Websites – the customer must be able to order/get the goods/services from the website. Generally okay for services, for goods the mark must be shown next to the goods, however for goods the preference is tags, labels, etc.
T-shirts – this area is complicated – contact your attorney.
Your attorney can advise you on this and other substantive issues. Consult them.