Hello and welcome to the site. Thank you for your question.
I run a small business dealing with online bookings for B&B's, as part of what I do I collect deposits for my clients which I pass on to them.
Do I need to include this money in my annual turnover?
You are the middle person collecting money on behalf of your clients and passing it to them. It is not your turnover and should not be included in your annual turnover.
Secondly I also pay various companies invoices on behalf my clients and assimilate them into a monthly bill along with my charges.
Do the companies charges need to be included in my turnover?
If you are just playing the role of a banker making payments on behalf of your clients, then these charges are not your turnover. You should be maintaining a control account to account for these recharges.
Finally one of the companies who's invoice I pay works under the reverse charge VAT system. I'm not VAT registered, but one of my clients is VAT registered. Does anyone need to pay VAT?
If the invoices are addressed to/from the companies who are VAT registered then no one need to pay VAT. More information on this can be found here
I hope this is helpful and answers your question.
If you have any other questions, please ask me before you rate my service – I’ll be happy to respond.