Boots instore have a glitch - the 75ml bottles of Soltan go through the till at buy 1 get five free 
I bought 12 bottles tonight for £11. It includes the kids high factor stuff and also the once a day. Factors 15, 30 and 50.
The lady on the till said its a glitch which combines the current BOGOF on sunscreen, with the 3for2 on travel mini bottles. She said it had been flagged to head office but that they weren't bothered!
Just thought I'd share 