All public entries will be carefully considered and shortlisted by a representative panel of official UK Eurovision Fan Club (OGAE UK) members.
Entries are also being sought from leading professional songwriters, with guidance from songwriter, publisher and new music consultant for the BBC, Greig Watts.
He said: “The Eurovision Song Contest just gets bigger and better and more exciting for me each year, and I’m sure Israel will deliver another amazing contest.
"I’m so happy to be involved this year for the UK; it really is a dream come true, and I’m looking forward to working with the team to get the strongest possible song and result we can for the UK, like we do on the world music stage.
"There’s no guaranteed song-writing formula for Eurovision as each year something different wins. I’m looking for melodic songs with impact for the arena as well as on TV. Songs that instantly hit you and never leave your brain.”
A final shortlist of songs will again be showcased to the UK public, who will have the chance to vote for their favourite in Eurovision: You Decide on BBC Two, details of which will be announced later this year.
Kate Phillips, controller entertainment commissioning at the BBC says: “I’m delighted that You Decide will be returning to BBC Two as the UK’s song search for Eurovision 2019 begins.
"We want to ensure that we cast the net far and wide to find the best entry possible, so we are really keen to hear from anyone who feels they have a song that has what it takes to do our country proud and bring Eurovision home.”
The 64th Eurovision Song Contest will take place at the Expo Tel Aviv in Tel Aviv, Israel with the semi finals broadcast on May 14 and 16, 2019 on BBC Four and the grand final will be broadcast on May 18, 2019 on BBC One.
The closing date for submissions is Friday, October 26, 2018.