I thought auto renewing contracts were now banned, if that's what you are referring to.
Yes, Line Rental Saver is a 12 month fixed contract. All other line rentals and Call Plans are normally ongoing, but you might want to negotiate a new contract if you can get better terms, as I might when my 12 month Anytime Plan discount expires

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Anyway I thought we were talking here about BT BB.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 19 Meg WBC