The Horizons project has already helped two dozen acts since 2014 - with radio airplay and UK festival appearances.
"Supporting new music is at the heart of what the BBC does across the whole of the UK, and internationally," said BBC Music's Jason Carter.
Bands and solo artists have until 12 February to apply.
"We're proud to support Horizons for a further year and see another 12 artists have a creative and potentially career changing 2016," said the Arts Council's Lisa Matthews.
"There's been some incredible opportunities created so far and we're looking forward with excitement to more incredible music experiences."
Solo artist Violet Skies said the 2015 project had meant a "mad year" for her.
She said: "I've been lucky enough to tick off a lot of things from my musical bucket list - The Great Escape, Festival No.6, SÅµn, Maida Vale and now, I'm looking forward to Eurosonic and SXSW festival in 2016.
"It's been a lovely little Welsh family of talented musicians and a really good support team - it's nice to turn up at festivals or a show knowing you have people there to help you."
A scheme to help new Welsh bands get wider exposure is set to return for a third year, backed by BBC Wales and the Arts Council of Wales.