Under the basis for filing of either "use in commerce" or "intent to use," prior to registration you must demonstrate that you have used the mark in commerce. The types of commerce encompassed in this definition are interstate, territorial, and between the United States and a foreign country. The basic difference between these two filing bases is whether you have started to use the mark on all the goods/services identified in your application.
If you have already used your mark in commerce, you may file under the "use in commerce" basis. If you have not yet used your mark, but intend to use it in the future, you must file under the "intent to use" basis. This means you have a bona fide intent to use the mark in commerce; that is, you have more than just an idea but are less than market ready (for example, having a business plan, creating samples products, or performing other initial business activities). An "intent to use" basis requires filing an additional form and fee prior to registration that are not required if you file under "use in commerce" at the outset. Use is established by providing the date of first use of the mark anywhere and the date of first use of the mark in commerce, as well as submitting a specimen (example) showing how you use the mark in commerce.
Under certain international agreements, you may file in the U.S. based on a foreign application, foreign registration, or international registration. See Trademark Manual of Examining Procedure Chapter 1000 and Chapter 1900 for specific requirements.