Just taken on a new client - he is a struggling sole-trader (joiner) who is receiving disabled working tax credit. He has managed a few one off jobs throughout the past eight months or so but no regular work coming in. He does a lot of voluntary work for the housing association which are his landlord and they refund him loss of earnings for doing this as well as covering his travel expenses - this money he has paid straight into his business account to try and raise some capital for advertising, etc.
It doesn't sound like voluntary work if they are paying him loss of earnings, so unless I am missing the point (most likely) then I would stick it down as sales...
It is voluntary work - he attends resident meetings and the like according to his expense forms. I believe that if someone is self-employed or employed they will cover loss of earnings and the back of the expense form he has to fill in it states how much HMRC will permit them to pay but it's the first time I've come across it. I wondered if I should code it to sales as 'consultancy' work or similar so I'm thinking along the same lines as you.