Thanks everyone for you thoughts. Amy, technically, all the group funds get applied for the benefit of the group according to the decisions of the committee. We have been, and continue to, run entirely on the charity of members. We have realised that this is unsustainable. The most obvious financial issue concerns our web presence (domain name, web hosting, website software, web services, etc.). In the past we have also encountered minor problems in not being able to pay a deposit for venue and equipment hire. In the past we have also provided travel sponsorship for some participants, though this was based on generous external sponsorship. We could offer small prizes for papers and presentations (especially for students). The committee will be responsible for deciding on the amount to be charged for the fees, adjustable annually. The point you raise about granting bodies not supporting membership fees is why many societies provide a members discount for their meetings, which exactly matches, or is slightly larger than the annual membership fee. I expect that this is what we would do here.