Your customers' mandates were set up under your old provider's Service User Number, so a new provider can only take them over through a Bacs bulk change, and that needs the old provider to take part. If it will, ask for a bulk change before the account closes, and customers won't need to re-sign. If it can't or won't, customers sign new mandates, and in the meantime you collect by payment link, card or bank transfer so no month goes unpaid.
In this article
The short version
- Your mandates sit under your old provider's Service User Number, so they can't simply be reused.
- A Bacs bulk change moves them without re-signing, but the old provider has to take part.
- With Adfin, 10 or more mandates move by bulk change; fewer than 10 sign a new mandate online.
- If the old provider has stopped trading, customers sign new mandates.
- Cover the gap with payment links, card on file or unique bank details for transfers.
What happens to your mandates when the account closes
A direct debit mandate is an instruction at your customer's bank, allowing collections under one Service User Number (SUN). If you collected through a provider without your own SUN, the mandates sit under the provider's number, not yours. Once your account closes, the provider stops submitting collections for you, and no other provider can collect under those mandates unless they're formally transferred.
The same applies whether the provider closed your account or the provider itself is shutting down, but the help you can expect differs. A provider that's still trading can take part in a transfer. One that has stopped trading may not be able to.
Before anything else, find out from the old provider:
- the date your account closes and the last date it will submit a collection
- whether it will take part in a Bacs bulk change to a new provider
- how to export your customer, mandate and payment history before you lose access
Can the mandates move without customers re-signing?
Yes, if your old provider takes part. In a Bacs bulk change, the old and new providers sign a bulk change deed, the old provider sends your mandate data across securely, and both providers' sponsoring banks approve the move. Your customers are told about the change and don't sign anything. Bacs's switching procedures give the old provider set tasks in a bulk change, including signing the deed and handing over the data, and Bacs expects the process to take about four to six weeks.
Two things can stop it. If the old provider has ceased trading and there's nobody to complete its side, the mandates can't be transferred, and every customer needs to sign a new mandate. And if your account closes sooner than a bulk change can be completed, ask both providers straight away whether the switch can still go ahead. If it can't, plan for customers to sign new mandates.
With Adfin, 10 or more mandates move through the Bacs bulk change and your clients don't re-sign. Adfin arranges the transfer with your old provider, sets a change date at least five weeks ahead and emails your clients on that date in your branding, and mandates become active three working days later. With fewer than 10, clients sign a new mandate online. Where the old provider can't take part, you send each client a mandate request to sign online.
How to keep money coming in while you switch
Between the last collection on the old account and the first on the new one, there's usually a gap. List every invoice due in that window and decide how each will be paid, so nobody is missed and nobody pays twice.
There are a few ways to collect in the meantime:
- Payment links by email, SMS or WhatsApp, so customers pay by card, Apple Pay, Google Pay or pay by bank from their phone. Pay by bank reaches you the same day.
- Card on file for regular payers, charged automatically when each invoice is due.
- Bank transfer to bank details unique to each customer, so their payment matches their invoice without anyone checking references.
In Adfin, a customer can be asked to pay their next invoice from a link and then set up a direct debit for the invoices after it. A card saved on file is charged automatically, with the customer told one business day before. Customers who haven't signed a new mandate are followed up by Adfin's collection agents by email, SMS or WhatsApp within rules you approve, each time with a link to pay the invoice in front of them.
A timeline for the first few weeks
A closure notice rarely arrives at a convenient time, so work in this order:
- On the day you hear: confirm the closure date, ask for a bulk change, and export your data.
- Within a week: open the new account, connect your accounting software and check which customers have collections due before the switch.
- Before the old account closes: tell customers what's happening, what name they'll see on their bank statement and what, if anything, they need to do. Send payment links for anything falling in the gap.
- On the change date, or once new mandates are signed: check every customer appears on the new provider, then follow up anyone missing.
- After the first collections: compare what was collected against what was due and clear any gaps by payment link.
Keep the old account open, if the provider allows it, until its last payout has landed, and keep its records, since a customer can still claim a refund on an earlier collection under the Direct Debit Guarantee.
Related guides
- What to tell clients before you switch direct debit provider (with template wording)
- Switching direct debit provider: what actually happens to your mandates
- Running two payment providers while you switch
- Switching payment provider: a complete guide
Common questions
Does my old provider have to help with a bulk change? Bacs's switching procedures give the old provider set tasks, such as signing the deed and sending the mandate data. If it has ceased trading or won't take part, customers sign new mandates.
Do customers have to sign a new mandate if my provider closed my account? Not if the old provider takes part in a Bacs bulk change. With Adfin, 10 or more mandates move that way without re-signing; with fewer than 10, customers sign online.
How long does a bulk change take? Bacs expects about four to six weeks. Adfin sets the change date at least five weeks ahead.
How do I collect payments while the switch is happening? Send payment links by email, SMS or WhatsApp, charge a card on file, or give customers unique bank details for a transfer.
What should I tell customers? That the business collecting is changing, what name they'll see on their statement, and whether they need to do anything. Send it before the old account closes.
What happens to refund claims on old collections? Customers keep their Direct Debit Guarantee rights. Keep your old provider's records, and ask how a late claim on an earlier collection would reach you.
Sources
- Bacs - The little Bacs guide to switching FM providers (accurate as of November 2026) https://www.bacs.co.uk/media/xglbtzor/little_bacs_guide_to_switching_fm_providers.pdf
- Pay.UK - The Direct Debit Guarantee (accurate as of November 2026) https://directdebit.co.uk/direct-debit-explained/direct-debit-guarantee/
- Adfin - Bulk migrate your direct debit mandates to Adfin (10+ mandates) (accurate as of November 2026) https://support.adfin.com/en/articles/12688044-bulk-migrate-your-direct-debit-mandates-to-adfin-10-mandates
- Adfin - Switch to Adfin direct debit self-serve (under 10 mandates) (accurate as of November 2026) https://support.adfin.com/en/articles/10199769-switch-to-adfin-direct-debit-self-serve-under-10-mandates
