'Cash purchases' are any payments you make to suppliers who you don't have an account with. You have to pay for these goods at the time when you buy them.
You might sometimes make Cash purchases from suppliers who you've never used before and so haven't yet set up an account with. And there may be some suppliers who you don't have an account with because you only use them very occasionally.
From time to time you might purchase goods and sundries - perhaps things like cable clips - from a local DIY retailer or hardware shop because you've run out of them and you need some to finish a job. Once again, if you don't have an account then these are Cash purchases.
Remember to keep all the invoices and receipts for Cash purchases safely, even if they're just for small amounts.
Cash purchases only include items that you buy for use in aerial installation, repairs or other business activities. They don't include things like tea and coffee bought for use at work. Don't include things like this here. They're covered elsewhere in the cash flow.