Based in Book St., London, Bedingfield debuted in the 1990s as a member of the Christian dance/electronic group The DNA Algorithm with her siblings Daniel Bedingfield and Nikola Rachelle. Throughout the 1990s and early 2000s, Bedingfield recorded rock and gospel songs for the Hillsong London Church, while Daniel went on to enjoy success with hits "Gotta Get Thru This" and "If You're Not The One".

Bedingfield recorded her first album Unwritten in 2004. The album contained primarily uptempo pop songs and was influenced by R&B music; it enjoyed international success with over 2.3 million copies sold worldwide. In 2007, she received a Grammy Award nomination for "Best Female Pop Vocal Performance" for the song "Unwritten". Bedingfield's second album N.B. (2007) yielded the singles "I Wanna Have Your Babies", "Soulmate" and "Say It Again". Bedingfield has achieved five top ten singles in the United Kingdom and, as of April 2008[update], she has sold over 2 million albums worldwide.[citation needed]

Bedingfield was born in Surrey (later moving to the Lewisham district of London) to New Zealand-born Molly and John Bedingfield who are both charity workers. She has three siblings; brothers Daniel and Joshua, and younger sister Nikola. Her interest in music was encouraged by her parents and she took guitar and piano lessons when she was younger.[not in citation given] When Bedingfield was a teenager, she and her siblings, Daniel and Nikola, formed the dance/electronic group, The DNA Algorithm. The group provided Bedingfield with the opportunity to explore different musical genres and expand her songwriting abilities. She provided vocals for the group which primarily performed dance-pop music about religion, independence and empowerment, themes that would later be found in her own solo compositions. The DNA Algorithm performed at several Christian music festivals before disbanding.[unreliable source?][not in citation given]

Bedingfield attended a year at the University of Greenwich, where she studied psychology, then left to concentrate on singing and songwriting. At first she recorded demos in the garages of friends who had recording studios, which she presented to record companies.[not in citation given] Throughout the 1990s and early 2000s, Bedingfield composed and recorded songs for the Hillsong London Church. In 2004, her recordings appeared on the church's live album Shout God's Fame and the children's album Jesus Is My Superhero by Hillsong Music Australia.

At age 14, Natasha sang vocals on Origins Refined Intricacy (Steelyard Records).

Bedingfield signed a recording contract with BMG UK & Ireland, through its imprint Phonogenic Records, in 2003. Her first album Unwritten was released in September 2004 and features collaborations with Steve Kipner, Danielle Brisebois, Wayne Rodrigues, Nick Lachey, James Reilly, Andrew Frampton, Wayne Wilkins, Kara DioGuardi, Guy Chambers, Patrick Leonard and the rapper Bizarre. The album contained uptempo pop rock songs and influences from R&B music. Bedingfield's lyrics focused on independence, opportunism and female empowerment. Reviews of the album were generally positive[citation needed] and it was described as a "well-made pop album for the new millennium" by Allmusic. The album debuted on the UK Albums Chart at number one and reached the top thirty in the United States. It sold well, reaching multi-platinum status in the United Kingdom and Gold status in the U.S. The first single released from the album was "Single", which reached number three on the UK Singles Chart. The song's lyrics, and its accompanying music video, depict Bedingfield's single lifestyle. "These Words" was released as the album's second single. The song became Bedingfield's first UK number one and U.S. top twenty single. "Unwritten" was released as the album's third single in 2004, the song reached number six on the UK Singles Chart and it also became the most played song on U.S. radio in 2006. "I Bruise Easily" was released as the album's fourth single, it did not perform as well as its predecessors but was still a moderate success, reaching number twelve on the UK Singles Chart.

In 2004, Bedingfield also appeared on the Girls Of FHM single, "Da Ya Think I'm Sexy?", alongside Tina Barrett (formerly of S Club 7) and Liz McClarnon (formerly of Atomic Kitten). The single peaked at number ten in the UK Top 40 charts.

At the 2005 Brit Awards, Bedingfield was nominated for four awards, though did not win any of her nominated categories. She was also nominated for an award at the 2006 Brit Awards, and in 2007 she was nominated for "Best Female Pop Vocal Performance" at the 2007 Grammy Awards, though was again unsuccessful in winning in any of her nominated categories.

In November 2006, Bedingfield released the DVD Live in New York City, which contained a live concert performance as well as music videos and a documentary. That month she recorded the Diane Warren-penned song "Still Here" for the film Rocky Balboa. The song, however, did not appear on the soundtrack although it was included on her second album.

Bedingfield's second album N.B. was released in Europe in April 2007. In North America (the U.S. and Canada), the album was released under the title "Pocketful of Sunshine" in January 2008. Bedingfield again collaborated with Kipner along with Eve, Wayne Wilkins, and Maroon 5 singer Adam Levine. The album takes influence from a variety of music styles such as R&B, reggae and electronica. Bedingfield commented that it differed from Unwritten because it represented her shifting priorities from being a single young woman to "dating, searching for a partner" and "looking for Mr Right". The album received mixed reviews by critics and peaked at number nine in the UK.