volunteering abroad

I have recently returned from the US after volunteering with an organisation for 10 months. Before that I had volunteered with the same organisation for 11 months and I was back in the UK for 5 months in between each voluntary trip. I called student finance yesterday and the said I can still be eligable for student finance as long as I can supply evidence. Would a letter from the organisation I worked with be enough evidence if it explains that I was volunteering? When filling out my student finance form, and it asks if I've lived outside the UK, should I say no, as technically my address was still my UK address and I didnt have a permanent address in the States?

You're right - you have not permanently lived outside the UK - your absences have been fixed term and temporary which doesn't affect your ordinary residence status at home.

I personally wouldn't mention the trips in your residence history - presumably while you were away you kept a UK bank account (with a UK address) and remained on the electoral register etc etc.

If it gets queried then either a letter showing the placement was fixed term or your visa information showing that you didn't have permission to stay in the US and work for longer than the periods concerned would be enough evidence.

So I found out today that my parents moved during the electoral registration and we missed our registration, so I will have a gap in my electoral roll. I do have a UK bank account that has proof of U.K. Address and the visas in my passport all have that they are temporary on them. I also have a letter from the organisation saying that I was volunteering voluntarily. Should I write a letter to student finances and tell them the situation? Will this be enough evidence that I was gone temporarily?