How can my bank pay a DD without my permission?

nyermen

Chalkius is right - there has to be a "mandate" in place (basically, permission). Otherwise the collection request would be refused by BACS. However, they can be set up automatically by a company without needing a written form/signature. As Jeremy Clarkson found out when he printed his account details claiming they were useless (and someone set up a charity DD on his behalf).

it can suddenly activate after a long period of time

Note that after 13 months of inactivity, they become known as "dormant" and permission (or a new mandate) must be sought before claiming - see this link:
https://www.directdebit.co.uk/DirectDebitExplained/FAQs/pages/inactivedirectdebits.aspx

[Deleted User]

nyermen wrote: »

Chalkius is right - there has to be a "mandate" in place (basically, permission). Otherwise the collection request would be refused by BACS. However, they can be set up automatically by a company without needing a written form/signature.

I suspect the mandate has been there all along and that this is satellite equipment insurance that the Op simply failed to cancel when they dispensed with Sky.

The Op doesn't appear to be in any hurry to update either of the two threads on the subject.