Do you need a registration in order to use a trademark?
No, there is no legal requirement to register or even apply for a mark before you can use it. In fact, it would be impossible in most cases to register a mark in the US before use. Unless a trademark application is based on a foreign registration, the applicant would be required to show usage of the applied-for mark on the relevant goods or services before the USPTO will issue a trademark registration. The US differs from certain foreign countries that enable registration of a mark without use.
It should come as no surprise that businesses all over the US operate without a trademark registration. Think about your own company. Did you apply for a trademark before you began doing business?
Why register a trademark if you can use it without a registration?
Not every mark should be applied for. In fact, it may be preferable to keep doing business without filing a trademark application. For example, if you have a very generic or descriptive mark, your chances of a successful registration would be substantially lower than that of a more distinctive mark. Another scenario that might warrant no filings is when your mark may be somewhat similar to another mark owned by a more vigilant company who may be monitoring new trademark applications. Staying under the radar does have its benefits in certain circumstances.
Assuming that your mark is not descriptive and not similar to any other trademarks known to you in your industry, then it may be worthwhile to consider registration. Of course, applying to register a mark is by no means a guarantee that the USPTO will grant the desired outcome. You may still have to overcome refusals to obtain a registration.
Hopefully, your trademark application process will lead to a registration that can provide you with significant benefits. A trademark registration provides the owner with certain legal presumptions that make it more difficult for a third party to challenge. For example, your mark will be presumed valid and ownership of the mark will be presumed as yours. In order for a challenger to argue otherwise, they would bear the burden showing invalidity or different ownership.
Basically, a trademark registration gives the owner an exclusive right to use the registered mark on the goods or services identified in the registration. If enough time passes, those rights become more difficult to challenge.
What are offensive and defensive benefits of a trademark registration?
Trademark registrations provide both offensive and defensive benefits. A registration would provide the owner with stronger grounds for alleging trademark infringement or opposing a trademark application. Suppose, however, that you have no intention of going on the offense. What kind of defense can a trademark registration provide?
One significant defensive benefit of a registration is having the USPTO as an ally in blocking the registration of subsequent applications for similar marks. This all happens without your knowledge or effort. The USPTO may block countless future applications and you would have invested no time or effort in this endeavor.
What if you want to continue using a mark after an abandoned trademark application?
In one sense, your legal rights after an abandoned trademark application may not be much different than your status prior to filing. From a legal perspective, the post-filing status of a failed trademark application may differ much from the pre-filing status. That being said, there may be some practical differences.
If the trademark examining attorney issues an Office Action, there will be a written record accessible to the public. Any reasons for refusing registration of your mark will be publicly available for anyone to see (if they know how). As discussed above, your filing may also catch the attention of a more aggressive trademark owner who can possibly send you a cease-and-desist letter.