If you are growing your business then you should consider pushing go cardless more.
It is okay to be waiting for payment if you just have one van, but with multiple vans, and ALL the associated expenses, then managing cashflow becomes an issue.
Go Cardless has the following advantages.
Team members don't have to handle cash and cheques.
You don't waste time chasing debt or processing hundreds of tiny sub-£50 payments
You will have cashflow to meet your expenses
Direct debit customers have a much higher retention rate
Make then sign up to direct debit before you do any work. Then you won't
waste time doing first cleans for customers who only want a one off.