Grouping expenses: is this allowed?

Are you VAT exempt or subject to VAT? If you are subject to VAT, I think it is better to book them separately, so that everything is in the correct vAT declaration.

But if you are vAT exempt, then I think: yes, fine, you can bundle them. As long as it is included in your accounts on an annual basis and you have the necessary invoices to prove (if necessary) where those costs come from.