For most productions, the use of cameras or phones during the production is not allowed unless encouraged by the cast. The recording of any event is prohibited.
You can bring a camera into the theatre, but this must stay packed away and cannot be taken out at any point during the show.
For certain productions, cameras (including mobile phone cameras) are not permitted in the venue - if this is the case, you will be informed at the point of purchase or emailed with more information if this is added to the performance following your purchase.