Q: What is the Date of First Use of Mark in Commerce ? The date of filing intent to use with USPTO? Or, is it the date I first use in interstate commerce or internationally? A: Neither. The "date of first use" or "date of first use anywhere" is the first time you affixed the mark to the goods (or packaging containing the goods) in the ordinary course of commerce, even if within your state. Note the wording in the online form adds "at least as early as", so the safe way and what almost everyone does is just use the same date for both, namely the date of first use in interstate commerce. Since the form says "at least as early as" you can always prove it was earlier (even before your filing date if that is the case) in litigation. Q: What is “use"? A. The date of first sale, or B. The date of first sample sent, or C. The date of first advertisement? A: Normally, for trademarks (marks used on goods) it is the date you first transported goods bearing the mark in commerce. (whether paid or not) so long as it was for primarily for business purposes. So, you want to pick a date you can prove, and that means you want to use a date for which you have a shipping document or a date for which you have a customer acknowledgment of receipt. (I typically use the date of receipt, as then it is not open to challenge) and the shipping document should preferably have the trademark so there is no doubt that what was shipped did, in fact bear the trademark. Advertisement dates work for service marks but should not be used as dates of first use for trademarks because ads are not affixed to the goods and thus leave room for attack in litigation. For service marks (marks used on services), advertisement dates are acceptable because that is how service marks are normally used. Since there are normally no goods being transported, ads are how the trademark is "associated or affixed" to the services. Q:The date must be after the date of filing intent to use, right? A: No, but that is the smarter date to use since making it earlier makes the dates suspicious and thus opens them up to question because it would be expected that a use (1a) application would have been filed if that was the case. Since the dates in the online form are automatically prefaced by "at least as early as" there is no need to state a date earlier than the filing date, even if that is the case, since in litigation you can prove an early date due to the "at least as early as" language automatically added.