Princesses Beatrice and Eugenie have broken royal protocol, but it's for a good reason.

With every passing day, we’re discovering more and more rules the royal family is bound by.

The latest one to ping our radar is that royals aren’t supposed to sign their names in public, just in case they risk having their signature forged.

As reported by News.com.au though, royal rebels Princesses Beatrice, 29, and Eugenie laughed off the threat of identity theft and did exactly that.

In their defence though, it was all for a good cause.

Their signatures appear on an artwork commissioned by their mum, Sarah Ferguson’s charity, Children In Crisis.

Thank you Teddy M for working on this amazing painting for @childrenincrisis and congratulations on creating one of @teddysphotos art guitars #art #music

A post shared by Sarah Ferguson (@sarahferguson15) on Jun 19, 2018 at 7:28am PDT

According to the homepage on the charity’s website, it provides “education, care and protection for forgotten children” all over the world.

The painting was created by British contemporary artist Teddy M, and appears on one of Ed Sheeran’s guitars.

It will be auctioned off to raise money for the charity.

“Thank you Teddy M for working on this amazing painting for @childrenincrisis and congratulations on creating one of @teddysphotos art guitars #art #music,” Fergie, 58, captioned a photo of the artwork on Instagram.

It’s not the first time Princess Eugenie has laughed in the face of royal protocol.

The 28-year-old also has her own personal Instagram account, which isn’t allowed for royals, as previously reported by Mamamia.

You may remember Meghan Markle, 36, had to shut down her blog and Instagram account in the lead up to her wedding to Prince Harry, 33.

According to Hello! magazine though, Eugenie gets a pass because she’s not actually a “working member of the royal family”, which means she doesn’t attend official engagements on behalf of the family.

So many rules – we can’t keep track.