AUDDIS, ADDACS and ARUDD are the Bacs services that tell you what's happened to a direct debit. AUDDIS reports new mandates a bank has rejected, ADDACS reports changes and cancellations to existing mandates, and ARUDD reports collections the payer's bank sent back unpaid. Each message carries a one-character reason code, and the code tells you whether to retry, get new details or talk to your customer.
In this article
The short version
- AUDDIS reports new mandates a bank rejected, ADDACS reports changes and cancellations, ARUDD reports returned collections.
- Each message carries a one-character reason code that tells you what to do next.
- ADDACS 1 means the customer cancelled; B means the account closed; R means a mandate is live again.
- ARUDD codes 4, 7, 8 and 9 point at your own notice or timing, not the customer's balance.
- With a payment provider, these reports go to the provider, not to you.
What AUDDIS, ADDACS and ARUDD do
The three services cover different moments in a mandate's life:
- AUDDIS (Automated Direct Debit Instruction Service) is how new mandates reach your customer's bank electronically. If the bank can't set one up, the AUDDIS report tells you why.
- ADDACS (Automated Direct Debit Amendment and Cancellation Service) is how a bank tells you that an existing mandate has been cancelled, amended or reinstated, usually without any word from your customer.
- ARUDD (Automated Return of Unpaid Direct Debits) is how a bank returns a collection it couldn't take, so the money never arrives.
If you have your own Service User Number, these reports come to you from Bacs. If you collect through a provider, the provider receives them and passes the outcome on, often by updating the mandate or the payment in your dashboard.
Providers word a few codes slightly differently, so if one in your report doesn't fit the descriptions below, ask your provider how it reads it.
ADDACS codes: changes and cancellations
ADDACS is likely to be the report you see most. Each code points to a different next step.
| Code | Meaning | What to do |
|---|---|---|
| 0 | Instruction cancelled, refer to payer | Contact your customer before assuming anything |
| 1 | Instruction cancelled by payer | Ask why, and get a new mandate if they're still a customer |
| 2 | Payer deceased | Stop collecting and handle the account personally |
| 3 | Account transferred to a new bank | Get the new details and a new mandate |
| B | Account closed | Get new details and a new mandate |
| C | Account transferred | The account has moved (lists differ on whether to a new branch or a new bank), so check the details with your customer |
| D | Advance notice disputed | Check what notice you sent and when |
| E | Instruction amended | Update your records before the next collection |
| R | Instruction reinstated | A cancelled mandate is live again, so collections can resume |
A cancellation isn't always the end of the relationship. Customers switch bank accounts, close old ones and occasionally cancel by mistake, so a short, friendly message asking them to sign a new mandate often sorts it out.
ARUDD codes: collections the bank sent back
An ARUDD return means you submitted a collection and the payer's bank didn't pay it. These are the codes you'll meet:
- 0, refer to payer: usually not enough money in the account on the day. A retry a few days later often works.
- 1, instruction cancelled: the mandate was cancelled before the collection.
- 2, payer deceased.
- 3, account transferred: you need the new details.
- 4, advance notice disputed: your customer says they weren't properly told the amount or date.
- 5, no account, or the wrong type of account.
- 6, no instruction: the bank holds no mandate for you.
- 7, amount differs: the collection didn't match the amount you notified.
- 8, amount not yet due: the collection was taken before the notified date.
- 9, presentation overdue: the collection was submitted too late.
- A, service user differs.
- B, account closed.
Codes 4, 7, 8 and 9 point at your own process, not your customer's balance. If you see them, check your notices and collection dates, because the same mistakes can lead to refund claims under the Direct Debit Guarantee.
AUDDIS codes: new mandates the bank rejected
An AUDDIS rejection means the mandate never went live, so any collection you'd planned against it won't happen. The codes fall into three groups.
Details you can correct and resubmit: I (payer reference not unique), L (incorrect account details), O (invalid reference), P (payer's name missing), Q (service user's name blank) and M (transaction code or user status incompatible). These are usually typing or set-up errors.
Accounts that can't take a direct debit, or have moved: 3 (account transferred), 5 (no account), 7 (amount on the instruction not zero), B (account closed), C (account transferred to a different branch), F (invalid account type), G (bank won't accept direct debits on this account) and N (transaction not allowed at the payer's branch). You'll need different account details or a different way to pay.
The customer or bank has ended it: 1 (cancelled by payer), 2 (payer deceased), 6 (no instruction), H (instruction expired) and K (cancelled by the paying bank).
Most of this is admin, and it only helps if somebody reads every message. With Adfin you don't need a Service User Number of your own, so these reports go to Adfin and you don't have to read Bacs files yourself. A returned collection is retried for free. If the retries don't work, the customer is asked to pay another way, and Adfin's collection agents follow up by email, SMS or WhatsApp on the schedule you approve.
Common questions
What's the difference between AUDDIS, ADDACS and ARUDD? AUDDIS lodges new mandates and reports rejections, ADDACS reports changes and cancellations to existing mandates, and ARUDD reports collections the payer's bank returned unpaid.
What does ADDACS code 1 mean? Your customer cancelled the direct debit at their bank. You need a new mandate to collect again.
What does ADDACS code B mean? The account has closed. Collections stop until your customer gives you new details and signs a new mandate.
What does ARUDD code 0 mean? Refer to payer, which usually means there wasn't enough money in the account. A retry a few days later often succeeds.
Do I have to stop collecting when an ADDACS message arrives? For a cancellation, closed account or deceased payer, yes. An amendment means updating your records, and a reinstatement means you can carry on.
Are indemnity claim codes the same as ADDACS codes? No. Indemnity claims have their own reasons and arrive separately, when a payer's bank has refunded a collection under the Direct Debit Guarantee.
Sources
- Bacs - Glossary (accurate as of October 2026) https://www.bacs.co.uk/resources/glossary/
- Bacs - AUDDIS (accurate as of October 2026) https://www.bacs.co.uk/bacs-schemes/direct-debit/services/auddis/
- 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/
