A trademark is published for opposition after the USPTO determines that your trademark application complies with all applicable laws, rules, and regulations.  Approximately 3-4 months after your trademark application is filed, a trademark examining attorney will review it.  If the examining attorney concludes that your application meets all legal requirements, it will approve your trademark for publication.  Conversely, if the examining attorney finds problems with your trademark application, he will issue a trademark office action explaining why he’s rejecting your application.  If you’re able to successfully overcome all of the issues raised in the office action, then the examining attorney will approve your trademark for publication.  Barring any unforeseen circumstances, your trademark will be published for opposition approximately two months after the examining attorney has approved your trademark for publication.

The publication period is a 30-day period in which anyone in the world can file a trademark opposition against your application.  A potential opposer can also request up to an additional 90 days in which to file a trademark opposition by submitting a request for an extension of time to oppose your application and paying the applicable government fees.  It isn’t unusual for a potential opposer to file an extension of time to oppose your application and then choose not to follow through with a formal opposition.  Sometimes an opposition is filed and that opposition needs to be resolved in some manner before the USPTO takes further action on your application.

If no opposition is filed and your trademark application was filed under either Section 1(a) (use in commerce) or Section 44(e) (U.S. application based on a foreign registration), then the USPTO will issue the Certificate of Registration about 6-8 weeks after the expiration of the opposition period.  On the other hand, if your trademark application was filed under Section 1(b) (intent to use), the USPTO will instead issue the Notice of Allowance.  You will then have six months in which to file the Statement of Use or a Request for an Extension of Time to file the Statement of Use.  Once the Statement of Use is filed and accepted, the USPTO will issue the Certificate of Registration.

One thing to note is that only trademarks approved for registration on the Principal Register (as opposed to the Supplemental Register) are published for opposition.  This means that your only opportunity to challenge a trademark approved for registration on the Supplemental Register is to wait until the trademark registration actually issues and then file a trademark cancellation with the Trademark Trial and Appeal Board (TTAB).