Clients who already pay you by direct debit through another provider can usually move without signing anything, through the Bacs bulk change process. Clients who pay by bank transfer, standing order or card need to sign a mandate once, so the work is in the message you send and the follow-up. Pick a moment such as a fee review, tell clients what will be collected and when, and chase the ones who haven't signed.
In this article
The short version
- Clients already on direct debit elsewhere can move by Bacs bulk change without signing anything.
- With Adfin, that applies to 10 or more mandates; with fewer, clients sign a new mandate.
- Clients paying by transfer, standing order or card sign once, so the message and follow-up matter most.
- Ask standing order payers to cancel theirs once the first direct debit date is confirmed.
- In the first month, watch for mandates that didn't go live, failed first collections and reconciliation.
Which route each client takes
If you're moving a whole client base, you'll usually have two groups, and they move differently.
Your clients already on direct debit with another provider can be moved in bulk. Under the Bacs bulk change process, the existing mandates transfer to the new provider, both providers' banks agree the change, your clients are told in writing before it happens, and nobody signs anything. With Adfin, this applies when you're moving 10 or more mandates. With fewer than 10, each of your clients signs a new mandate, which is quicker for you to arrange than a bulk change.
Clients who pay you any other way, by bank transfer, standing order or card, need to sign a mandate for the first time. That's usually your bigger group and the slower job, because every one of them has to act.
| Client group | What they do | What you do |
|---|---|---|
| On direct debit elsewhere (10 or more mandates) | Nothing beyond reading your notice | Agree a change date and send the notice |
| On direct debit elsewhere (fewer than 10) | Sign a new mandate | Send the link and chase |
| Paying by transfer, standing order or card | Sign a mandate | Send the link, chase, and confirm when any standing order should stop |
What to sort out before you start
A few things are easier to fix now than halfway through:
- Clean up your client list. Remove clients who've left, merge duplicates and check every email address and mobile number, because the mandate request is only as good as the contact details it goes to.
- Decide the amounts and dates. A mandate only gives you permission to collect, so you need a clear schedule of what each client pays and when, whether that's a fixed monthly fee or invoices that vary.
- Choose a moment. A fee review, the new financial year or renewing engagement letters all give clients a reason for the change. A mandate request that arrives with a reason tends to get signed faster than one that arrives on its own.
- Plan the handover for standing orders. Clients paying by standing order have to cancel it themselves at their bank, so tell them to do it once their first direct debit date is confirmed, or some will pay you twice that month.
If some clients are moving from another direct debit provider, the bulk change is arranged between the providers and their banks, so ask your new provider for the timetable and keep collecting through the old one until the change date.
How to get clients to sign
Keep the message short and cover five things: what's changing, the date of the first collection, the amount or how it's worked out, what the client needs to do, and who to reply to with questions. It helps to answer the two worries clients tend to have before they ask:
- Their protection: under the Direct Debit Guarantee, their bank refunds any payment taken in error, in full and straight away, and they can cancel at any time through their bank.
- Whether you can take what you like: you can't. They're told the amount and the date before every collection.
Send the request where your client will actually see it. For a lot of small business owners that's a text or WhatsApp message, not an email to a shared inbox. Then follow up on a schedule, because the clients who don't sign straight away tend to need a reminder or two. When Cloud Accounting Support Services moved its clients across, 89% signed their new mandate within three days.
Adfin sends the mandate link by email, SMS or WhatsApp, and its collection agents chase the clients who haven't signed, on the timing and in the tone you set. If an invoice falls due before a client signs, you can send them a payment link to pay that one by card or bank, and set up the direct debit afterwards.
What to check in the first month
Once your collections start, keep an eye on three things.
On a bulk change, a few mandates may not go live, usually because the client's account has closed or moved since they signed the original. Your provider will tell you which ones, and you'll need to send those clients a new mandate link.
A first collection can also fail for ordinary reasons, such as the client moving money out of the account on the day it's collected. Adfin retries failed direct debits for free and charges nothing when one fails, and if the retries don't work the client is asked to pay another way.
Finally, check your reconciliation. Your money now arrives on a different rhythm, a few working days after each collection, so the first month's bank reconciliation can look unfamiliar even when everything has worked. Make sure each payment has matched the right invoice in Xero or QuickBooks, and watch for any client who paid by standing order as well.
Common questions
Do clients have to sign a new mandate if I change direct debit provider? Not on a bulk change. With Adfin, 10 or more mandates move through the Bacs bulk change process without clients signing anything; with fewer than 10, clients sign a new mandate.
Will collections stop while clients move? They shouldn't. You keep collecting through the old provider until the change date, and clients get written notice before it.
How do I move clients who pay by standing order? Ask them to sign a mandate, then to cancel their standing order at their bank once the first direct debit date is confirmed.
What should the message to clients say? What's changing, the first collection date, the amount, what they need to do and who to ask, plus a line on the Direct Debit Guarantee.
How quickly do clients sign? Many sign within days if the request is clear and followed up. One accountancy practice saw 89% of clients sign within three days.
What if a client refuses direct debit? Offer another way to pay, such as a payment link by card or pay by bank, and keep chasing that client by reminder.
Sources
- Bacs - The little Bacs guide to switching facilities management provider (accurate as of October 2026) https://www.bacs.co.uk/media/xglbtzor/little_bacs_guide_to_switching_fm_providers.pdf
- Bacs - Direct Debit: an introduction to the service (accurate as of October 2026) https://www.bacs.co.uk/media/pu4bmlzs/dd_introduction.pdf
- Pay.UK (Direct Debit) - The Direct Debit Guarantee (accurate as of October 2026) https://www.directdebit.co.uk/direct-debit-explained/direct-debit-guarantee/
- Adfin Help Centre - Bulk-migrate your direct debit mandates to Adfin (10+ mandates) (accurate as of October 2026) https://support.adfin.com/en/articles/12688044-bulk-migrate-your-direct-debit-mandates-to-adfin-10-mandates
- Adfin - Pricing (accurate as of October 2026) https://www.adfin.com/pricing
