The Canadian pop star has entered full-on planning mode and hinted her marriage ceremony to the Nickelback rocker will be a lavish affair, but she is keeping some romantic details secret until the big day.
She teased: ''I'm planning a wedding ... some things will be a surprise. Some things will be what he likes and still will surprise him! Our wedding song will be a duet we recorded together for my new album.''
The 'Girlfriend' singer fell for Chad last summer while the pair were recording songs together for her fifth studio album in Los Angeles.
Speaking to the new UK issue of HELLO! magazine, she gushed: ''It evolved into this wonderful thing. When you're sitting there signing across from somebody into the microphone and you're singing a love song, you start to develop these feelings for that person, and it just blossomed into this thing.''
The loved-up pair have vowed to never leave each other's sides and are following each other around the world on tour so they don't grow apart.
Avril - who was previously married to Sum 41 frontman Deryck Whibley - explained: ''We have decided to spend a majority of our time together ... We want to make sure that we are on the same road together versus two separate paths. He has been with me the past year, making my record.
''I was on tour with him [in Sydney, Australia], and he is going to come on tour with me. When were hanging out and having a good time, I never want it to end.''
The feisty star is famed for her punk rock style and fearless attitude, which she admits is what attracted Chad to her in the first place.