Gwen Stefani spends $1,000 a week on her nails.

The 'Voice' USA mentor is reportedly addicted to manicures and pays a professional beautician to visit her Beverly Hills mansion to ensure her nail polish is immaculate and matches her outfits at all times.

A source told Star magazine: ''Gwen spends $1,000 a week on her manicures. She pays $300 for her manicurist from Nails by Design to come to her Beverly Hills home, and the other weeks she did that three times. The amount she spends on her nails is unreal.''

The blonde beauty, who has three sons, Kingston, seven, Zuma, five, and Apollo, six months, with rocker husband Gavin Rossdale, previously admitted she hates when her nails aren't perfect.

She said: ''When my nails are done, I feel more complete, more ready.''

The No Doubt frontwoman, 44, also once confessed she is extremely vain, joking that could be her ''middle name''.

During an interview in 2011, she said: ''I mean, I'm very vain. That would be my middle name. Of course I am, you know what I mean? I love the visual.''