The couple applied to U.S. Patent and Trademark Office on January 26 to own the name 'Blue Ivy', but have been unsuccessful.
On Tuesday (16 October), a judge instead sided with a party planning firm in Boston, Massachusetts, named Blue Ivy Events. The company have reportedly been using the 'Blue Ivy' name since 2009.
Beyonce and Jay-Z must be disappointed, as according to MyFoxBoston.com, the couple had plans to start a children's clothing company using Blue Ivy's name.
Beyonce with daughter, Blue Ivy Carter, posted by ChannelORANGE on Twitter.
However, Blue Ivy is already a star - in January, she made US Billboard chart history after becoming the youngest ever artist to place on the Billboard Top R&B/Hip-Hop Songs chart.
She was featured in Jay-Z's track 'Glory', which had the sound of her crying.
The song also featured the lyrics: "the most amazing feeling I feel / Words can't describe what a feeling, for real / Baby I'll paint the sky blue / My greatest creation was you."
Listen to the song below:
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