Yes, they just turn a key to open them. Some staff have ticket-sized cards that open them, or a smartcard that opens them.

Valid tickets may be rejected by barriers, and invalid tickets may be accepted by barriers. Ticketing in Great Britain is extremely complicated (the routeing guide has several thousand pages and includes a hundred or so maps), and magnetic strip tickets only hold something like 8 bytes of data. Although some tickets are now e-tickets in the form of barcodes, it seems that train companies have not invested in improving barrier programming.

Barriers can be set to reject certain tickets for revenue protection purposes, often used to force railcard holders to present their railcards to a staff member for inspection.

When no staff are available, barriers must be left open, as passengers must not be left inside stations unable to exit. In case staff forget to do this, pushing a barrier forcefully will also cause it to open.

Some barrier lines only have staff available by video link.