From their website ...
http://www.slimmingworld.com/information/clubrules.aspx [*] Commitment fees (back fees) are payable if a member misses a week. Exceptions to this are: [*]Shift Workers - provided the shift worker notifies the Consultant, in advance, of which weeks they cannot attend because they have to work. If the shift worker misses weeks for other reasons eg social events, then they must pay for the missed weeks. [*]Holiday and Illness - in a period of any one year, 6 weeks in total are allowed to be missed without charge, for holidays and illness providing: a) in the case of holidays, the member notifies the Consultant in advance; [*]Shift Workers - provided the shift worker notifies the Consultant, in advance, of which weeks they cannot attend because they have to work. If the shift worker misses weeks for other reasons eg social events, then they must pay for the missed weeks. [*]in the case of holidays, the member notifies the Consultant in advance; [*]in the case of illness, the member is genuinely unfit to attend and notifies the Consultant as soon as possible. In the case of hospitalisation they would automatically be exempt from back fees, for that week.