'Cash purchases' are any payments you make to suppliers of goods and services with whom you do not have an account. For example these might include purchases of fuel from a petrol filling station that you do not have an account with.
Remember to keep safely any invoices and receipts for Cash purchases.
Don't include here other costs involved in running your vehicles such as servicing, repairs, spare parts, tolls and so on. These will be dealt with later in the cash flow.