It changed last year in my country, we no longer have direct debit, it is now called e-invoice. You sign up for it and start getting invoices in your bank account then it is just one click to pay or you can enable auto-pay, so its essentially direct debit which you can enable/disable at any time.

But when I did have direct debit it always included the maximum pay amount which I usually set 2x the amount of average bill so if utility company makes a mistake payment will not go through.