No. A direct debit mandate is an authority your customer gives to one specific business, and it cannot be moved to a different one.
Why not
The direct debit guarantee sits behind every mandate. It gives your customer the right to an immediate refund from their bank if a payment is taken in error, and it works because the mandate names the organisation allowed to collect. Moving a mandate from one business to another changes who holds that authority, which is a change your customer has not agreed to. That protection is the whole point of the guarantee, so the scheme does not allow it.
This applies whether the second business is a new legal entity, a group company, or another Adfin account you also own.
What to do instead
Ask your customer to set up a new mandate. You can send the request from Adfin in the usual way, and once it is signed, collection carries on as normal.
Things this is not
Two similar sounding changes that are possible, so it is worth being clear which one you need:
Moving from another provider to Adfin. Same business, different provider. Existing mandates can come across without your customers signing anything new. See Switching to Adfin: two routes, one goal and Bulk-migrate your direct debit mandates to Adfin.
Your customer changing their own bank account. Same business, same mandate. This is not something you or Adfin can start. If your customer moves banks using the Current Account Switch Service, their mandate moves with them and the new account details reach Adfin automatically, so there is nothing for you to do.