You may need a publisher if you:
Have 10 or more songs that are broad pitches and commercially competitive. By commercially competitive, I mean that a publisher would have no hesitation playing them for anyone because they stand up to anything on the radio in your genre. Broad pitches are songs that could be pitched to many different artists.
Already have some song activity at an independent level and want to try to move up to the big leagues.
Are an artist looking for a record deal. A good publisher can often help an artist get a record deal, but you should do a LOT of homework to make sure you are signing with a reputable publisher.
You probably don’t need a publisher if:
You only have a couple of commercially competitive songs. Publishers need to see more volume than that.
You already have a connection that helps you get songs recorded.
You aren’t really interested in getting songs recorded commercially.
You want to hang on to all of your publishing. Publishers are going to demand 50-100% of the publishing on all of your songs. For new writers, it’s almost always 100%. If you aren’t willing to give that up, there’s no need to meet with a publisher. (Note: The Songwriter always keeps the writer’s share of a song. We are taking about publisher’s share only here.)