When creating a Direct Debit, you have the option to utilise a "End Date". This does not cancel the instruction but will cease any further payments being taken.
To amend this once the payer has been created you can follow these steps:
If you possess your own Service User Number (also known as BANK SUN)
SmartDebit allows OWN SUN to amend the final collection date themselves. If you select the "Edit" button in the individual's page within SmartDebit, this will enable you to edit this field:
If you possess a Service User Number which is provided by SmartDebit (also known as FM Sun)
The SmartDebit customer support team are happy to amend any End Dates, upon receipt of an email to email@example.com detailing the request (containing the Payer's Bacs Reference as well as the new date).