Are trademarks markings essential?

Trademark Essential Trademark Law Intellectual Property

No, but they are important and should be used. It is suggested that the trademark claimant use “tm” or “sm” (servicemark) for marks which are claimed as the exclusive property of the trademark owner, but not yet registered. If your client has registered its mark, it may use ® (or “Registered in the U.S. Patent and Trademark Office” or Reg. U.S. Pat & Tm. Off.”) which should be placed somewhere near the trademark or the legend asterisked to the mark itself.