For a minimum donation of £5, you can get a mini manicure at one of over 20 manicure stations that will be set up around the square and all proceeds will be given to CoppaFeel.
I lost my granddad to breast cancer (it affects men too although it's much less common), so this is a charity close to my own heart and will be popping down for a manicure on the day. If you'd like to take part, you can book your slot via the Birchbox website.
There's also a specially designed t-shirt been created by illustrator Sally Faye Cotterill available to purchase at for £12 from the Birchbox website - again, all proceeds will go towards CoppaFeel.
I'd love to see you there - make sure to tweet a photo of your nails on the day using the #BirchboxManithon!