Recording reimbursements for volunteering and work expenses

Hello there, I would be grateful if someone could advise me on the right approach to the below please. I do a fair bit of volunteering and as a disabled person I am reimbursed in full for my transport costs, e.g. taxis. As the money goes into the same account as for my business and I wanted to do things correctly, I queried this in 2014 and was told by someone on the HMRC phone support line that I should just ignore this on my tax return and that there was no need to declare the travel costs or the reimbursement. This made sense to me as it seems like a straight spend/reimburse transaction with no gain or loss. My second situation is for reimbursement of expenses for work, both as an employee an as part of my self-employment. For my employment, I am fairly sure I'm being taxed on my transport as well as my salary. Sometimes the transport costs can be as high as £300-£400 as month so a fair bit of what I receive at the end of the month even before my salary. Is this correct or can I claim the tax back on the travel reimbursements? My public sector employer said this isn't their responsibility to help with and that I should just ask HMRC to get this refunded, but I can't find anything about doing this on any other forum, so question if this is true or HR just passing me on. As far as my self-employment is concerned, should I declare the repayment of costs for tax purposes even though I'm not gaining or losing anything here? I was told to just disregard this and only declare expenses which were not reimbursed (e.g. phone bills, office supplies). On a slightly different point, I'm also in receipt of benefits that will be means tested. Can I disregard the reimbursements as they are not actually income but just balancing out my own expenses? Otherwise I'd effectively be declaring earnings that aren't earnings as they don't increase my total balance at the end of the month. Any advice much appreciated. I just went on the advice I was given 10 years ago, but especially for the benefits issue if I get this wrong I could be in serious trouble. I'm scared to talk to HMRC by phone as each time I call the tone of the operators always makes me anxious as I get the feeling they always think I've automatically done something wrong. I struggle to take in a lot of information verbally all at once which doesn't help either. Thanks in advance.

Hi 

As the money from volunteering is basically a remibursement of costs there is no need to declare this anywhere as you do not get paid for the work done as a volunteer.  
For the transport cost for your PAYE employment, you would only be able to claim any business related costs. Normal commute to work cannot be claimed - Claim tax relief for your job expenses.
For the self employed expenses, you declare all income received. You can then claim any reimbursement as expenses - Expenses if you're self-employed.  
For the means tested benefits you would need to check this with the DWP.

Thank you