It is advisable, but not required. If your songs are not registered with a PRO, we suggest that you register them before or shortly after making a submission to a licensing opportunity.
For musicians, Performance Rights Organizations exist to collect and distribute royalties on the behalf of musicians and other audio and video artists for the use of their musical compositions (i.e. lyrics and musical notes) by others. You may be a registered member of a performance rights society (PRS), but that does not mean that your songs are registered. Oftentimes, when artists sign up with a PRO, they will also register their entire catalog of songs. Other artists register only a few songs. You must have registered your songs with a PRO to receive royalties through the PRO for songs that are performed.