A direct debit mandate, formally a Direct Debit Instruction, is your customer's authority to their own bank to let you collect from their account. It's valid when it uses the scheme's wording and layout, your sponsoring bank has approved the design, the customer hasn't added any limits to it, and you (not the customer) have lodged it with their bank. Once it's in place it runs until someone cancels it, and it covers different amounts as long as you give notice.
In this article
The short version
- A mandate is your customer's instruction to their own bank, letting you collect varying amounts with advance notice.
- It must use the Bacs wording and layout, be approved by your sponsoring bank, carry no added limits and be lodged by you.
- A customer can't set up your direct debit in their banking app; that usually creates a standing order.
- Mandates have no end date, so any fixed term belongs in your contract.
- Switching to Adfin with 10 or more mandates, customers don't sign anything; with fewer, they sign a new mandate.
What a mandate is
The mandate is an instruction from your customer to their bank. It authorises you to collect from their account, in varying amounts, provided they've had advance notice of each amount and date. You're named in it, but the authority sits between your customer and their bank.
Your customer can cancel it at any time by contacting their bank, without speaking to you first. You find out when the bank's cancellation message reaches you, through the Bacs service called ADDACS (it reports amended and cancelled mandates). Cancelling the mandate doesn't cancel what they owe you, though. The contract with your customer is separate, and the debt stands.
A mandate has no end date and no spending limit. It stays open until your customer, their bank or you cancel it, so a fixed contract term, a price or a cap belongs in your terms of business. Because the amount can change, you don't need a new mandate when your fees go up or a bill varies from month to month. You just tell the customer the new amount before you collect it.
What makes a mandate valid
Bacs publishes templates for the Direct Debit Instruction, and the rules attached to them are short and strict:
- Every instruction must keep all the required wording, in the same order as the template. You can put your branding around it, but the fields and the Direct Debit Guarantee text stay as published.
- Your sponsoring bank has to approve the design in writing before you send it out, and the same goes for using the Direct Debit logo.
- You have to check the form is complete before it goes to your customer's bank.
- Your customer can't add amount or date restrictions. A cap written in the margin turns it into something the scheme doesn't recognise, so the form needs redoing.
- Only you can lodge the instruction with your customer's bank. Your customer can't do it for you.
The last rule tends to cause the most confusion. Customers sometimes say they've set up the direct debit themselves in online banking. What they've almost always created is a standing order, and your first collection will fail because their bank holds no instruction for you. When you hear it, thank them and send your mandate link anyway.
If you collect through a provider, its sign-up form is the approved one and it lodges each instruction for you.
Paper and online mandates
A paper mandate is signed, returned to you and then lodged with your customer's bank, which works but is slow.
Most businesses now sign customers up online or over the phone, which Bacs calls paperless direct debit. It comes with extra conditions. The organisation needs to be using AUDDIS, the Bacs service that sends new instructions to banks electronically, and its bank has to approve the scripts, confirmation letters and online screens. The organisation is also responsible for verifying the customer's identity, account details and address.
After an online or phone sign-up, your customer has to receive written confirmation within three working days. If the first collection is due within a month, that confirmation has to include the advance notice and arrive in time to give the full notice period.
You'd only deal with this directly if you held your own Service User Number. Collecting through a provider means it has the AUDDIS set-up and the paperless approvals, so you send a link and your customer signs on their phone.
How to keep your mandates collecting
Most mandate problems are about admin, and a few habits keep them small:
- Ask for the mandate at the point of agreement. Sending a link with the engagement letter, proposal or first invoice gets it signed while the customer is paying attention.
- Chase unsigned mandates on a schedule. A customer who has agreed to pay by direct debit but hasn't signed tends to need only a reminder or two.
- Act on cancellation and amendment messages the week they arrive, so you can contact the customer before the next collection date comes round.
- Clear out mandates raised by mistake, such as duplicates or customers who never started, so your list shows what you can actually collect.
- Send advance notice for every collection, and keep a copy. If a customer ever claims a refund, your notice is your evidence.
Adfin sends the mandate link by email, SMS or WhatsApp and chases unsigned mandates automatically, and its AI Customer Agents follow up unpaid invoices using the timing and channels you choose. If the first invoice is due before the customer signs, you can send a payment link for that invoice by card or bank and set up the direct debit afterwards.
If you're switching provider, what happens to your existing mandates depends on how many you have. With 10 or more, Adfin moves them across through the Bacs bulk change process and your customers don't sign anything. With fewer than 10, each customer signs a new mandate.
Common questions
What makes a direct debit mandate valid? It uses the scheme's wording and layout, your sponsoring bank has approved the design, the customer hasn't added any amount or date restrictions, and you've lodged it with their bank.
Can my customer set up a direct debit themselves? No. Only the organisation collecting the money can lodge the instruction. A customer who sets something up in their banking app has usually created a standing order.
How long does a direct debit mandate last? Until your customer, their bank or you cancel it. A mandate has no end date, so any fixed term belongs in your contract.
Do I need a new mandate if my prices change? No. A mandate covers varying amounts, so you just give your customer advance notice of the new amount and date.
What do I need for online or phone sign-ups? The organisation needs the AUDDIS service, bank approval of its sign-up process and its own customer checks, and has to send confirmation within three working days. A payment provider takes care of these for you.
Do customers have to sign again if I switch provider? Not with Adfin if you have 10 or more mandates: they move through the Bacs bulk change process and customers don't sign anything. With fewer than 10, customers sign a new Adfin mandate.
Sources
- Bacs - Direct Debit Instruction templates and logo (accurate as of October 2026) https://www.bacs.co.uk/resources/direct-debit-instruction-templates-and-logo/
- Bacs - Paperless Direct Debit (accurate as of October 2026) https://www.bacs.co.uk/bacs-schemes/direct-debit/services/paperless-direct-debit/
- Bacs - AUDDIS (accurate as of October 2026) https://www.bacs.co.uk/bacs-schemes/direct-debit/services/auddis/
- 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 - Next-generation direct debit (accurate as of October 2026) https://www.adfin.com/direct-debit-payments
