The following occurs when a debit order premium goes unmet:

Some insurer skip one month’s cover where premium goes unpaid twice in each month. Otherwise a double debit will be raised at the next deduction date and if the double debit is unmet then the policy is canceled retroactively to the date of the first unmet premium.

The insurer will cancel immediate if he payment is payment stopped as opposed to an RD payment

The insurer will cancel immediately if the first debit unmet (no grace period)