A little history into how the signed tenner came about.

The signed tenners are from the exhibition (Santa's Ghetto) "Exit through the gift shop".

After the massive success of the 2002 exhibition Banksy knew he needed a gimmick for the 2004 exhibition "Exit through the gift shop, and what better way than to use something that he already had, the Banksy tenner, these were stored away in the back room, on the first floor of his secret London studio.

The first 500 through the doors would pay £10 entrance, and in return be given a signed Banksy tenner inside a signed envelope (Clever), Banksy had the gimmick he wanted for the exhibition, which wowed everyone that visited, most pieces were bought before the exhibition opened its doors, with some great names exhibiting their goods, all critics voting this the exhibition to beat all exhibitions.

The next time these were used is at the Dismaland Theme Park WSM 2015, some lucky punters were given these by staff at various stalls along with postcards, the certificate and stamped envelope, you are looking at one here

This is where the signed Banksy tenners came from, many are floating about, with a lot kept has keepsakes.

I cannot confirm that all these were signed by Banksy himself, they are written in black pen, not black marker, but POW, "Pest control" will not authenticate these tenners has to do so would leave them open to prosecution for de-facing the British monarch, and attempted counterfeit of the British currency.