Expenses and re-invoicing
There are two types of expenses to be reimbursed to be aware of. Expenses that you individually make for your own company, and expenses that your company makes and then re-invoices to your customer.
Expenses that you make on behalf of your own company needs to have your company name as the stated buyer on the record, not your own name unless you run a sole trader business. If you have subscriptions in your own name you need to talk to the supplier and change it to the company name.
Expenses made on behalf of your customers are usually technically speaking not “expenses”, but rather costs that should be re-invoiced. They are bookkept as costs in your own accounting, and then you add your purchase value excluding VAT to your customer invoice, and add the same type of VAT as the rest of your invoice no matter the type of VAT on the purchase. The original receipts for the expenses you keep for yourself. An actual “expense” is when you temporarily borrow money to your customer by paying something on behalf of your customer, and then you hand over the receipts to the customer and get a reimbursement for your expenses.
The expenses will be bookkept as costs in your customer’s accounting, and the records for these expenses needs to have your customer as the stated official buyer. If it’s your company’s name of the records you need to bookkeep them in your accounting and then re-invoice your customer for them.