If you are looking to take advantage of the VAT deferral scheme for payments due between 20th March 2020 and 30th June 2020 you MUST cancel your Direct Debit to ensure HMRC do not take payment.

You do not need to tell HMRC that you are deferring the payment but they will still collect the VAT due if you do not cancel the DD.

Please also remember that you should continue to file your VAT returns as normal,  deferred payments will not attract interest or penalties and all deferred VAT is then due on or before 31st March 2020.
For more information please check out HMRC’s website: https://www.gov.uk/guidance/deferral-of-vat-payments-due-to-coronavirus-covid-19