AUDDIS & Migration

AUDDIS is the Automated Direct Debit Instruction Service.  It is generally considered to now be best practice for setting up direct debits with the bank and is now mandatory for new Service Users that submit direct to Bacs.

Using AUDDIS offers a number of benefits:

Box Icon Lower cost to process

Lower cost to process

Box Icon DDI easier to identify

DDI easier to identify

Box Icon Significant reduction in unpaids

Significant reduction in unpaids

Box Icon Eliminates paper from the system

Eliminates paper from the system

Box Icon Better service quality

Better service quality

Box Icon Improved image of scheme

Improved image of scheme

Box Icon Reduces errors

Reduces errors

Box Icon One off Direct Debits allowed

One off Direct Debits allowed

AUDDIS References

The reference used in a Direct Debit Instruction (DDI) may be up to 18 characters long and must be a minimum of 6 characters. It must be lodged with the paying banks exactly as it appears on a signed DDI. It must be unique for the sort code, account number and SUN to ensure that the paying banks can accurately match Direct Debits to DDIs.

Collections from an AUDDIS Direct Debit Instruction must contain the ‘core reference’ and may also contain a variable element, identifying that particular claim. (The variable element is as added to the end of the reference i.e. a suffix not a prefix).

AUDDIS Transaction Codes

New Direct Debit Instruction (DDI) details must be stored for AUDDIS submission. Should you choose to send cancellation advises, then cancelled DDI details must also be stored for AUDDIS submission. Each data record is a lodgement or cancellation that a Service User wishes to make. Submissions must have an AUDDIS transaction code allocated to it:

Transaction Code Details Mandatory / Optional
0N (zero N) For a new DDI, or to re-instate a payer or Service User cancelled DDI. Mandatory
0C (zero C) To cancel an existing Direct Debit Instruction at the paying bank. Optional
0S (zero S) To convert an existing non-AUDDIS Direct Debit Instruction to AUDDIS.  Only used at time of migration Mandatory
0C/0N (zero C /zero N) To amend a direct debit instruction these may be sent in the same file. (Rule: this pair of codes should not be sent on receipt of an ADDACS report) Optional

AUDDIS File (Submission)

As with your collection process, the AUDDIS cycle is based on Bacs’ three-day cycle. As the advises have no financial value (£0.00 value), AUDDIS files are processed on receipt by Bacs, regardless of any processing date allocated in the file submitted.

All Bacs advises are processed on a 3-day cycle.

Day 1

Input Day

Service Users / bureau submit their files for Bacs processing before 10.30pm. On receipt, the Bacs system validates file and advice formats. Overnight, Bacs processes the AUDDIS advises.

Day 2

Processing Day

In the morning, files are sent to the member banks. Overnight, the banks process the AUDDIS advises.

Day 3

Entry Day

Advises that cannot be processed are returned to Bacs with an appropriate reason code. AUDDIS advises passing bank validation are applied to the bank accounts. Invalid DDI's are returned to Bacs for overnight processing by Bacs.

Day 4 / 5

Lodgement Failures

Bank Returned AUDDIS Advice Reports are available for service users to process.

AUDDIS File (Timescales)

Service Users have the opportunity sign-up payers whenever they wish and make collections on every working day of the year under the rules of the Direct Debit scheme. However, processing times and reconciling efficiently, along with specific business needs, should all be considered when selecting dates.

There are firm timescales for lodgement, collections and reports under the direct debit scheme, making it possible for Service Users to achieve optimum timescales within their direct debit process.  The level of automation a Service User is also a factor in the overall speed of a Service User’s direct debit process – from sign up to collections and reconciliation.

In terms of the best time frame to submit your AUDDIS file and then the collections file, Service Users MUST:


  1. Mandatory

    The Service User must allow at least 2 working days between lodgement and collection (mandatory)

  2. Best practice

    The Service User should allow at least 5 days between lodgement and collection (best practice)


With the above in mind, its recommended to allow at least five working days between lodgement and collection, allowing time to reconcile AUDDIS reports that will occur up to two days after lodgement.  This makes sense as ensures when it comes to submission of the collection file, it contains the least amount of errors.

AUDDIS Failures (Lodgement)

As with your collection processes, you will be notified by Bacs and the paying banks of any instructions that could not be processed. Your processes and systems must incorporate the retrieval and reconciliation of the AUDDIS related Bacs reports. AUDDIS lodgement failures occur at time of:


  1. Submission

    Submission when Bacs processes AUDDIS files, in the AUDDIS Input Report / AUDDIS Acceptance Advice

  2. Lodgement

    Lodgement when the banks process AUDDIS DDIs, in the Bank Returned AUDDIS Advice Report<


Bacs reports are accessed via the Payment Services Website or a Bacstel-IP application. On receipt of AUDDIS lodgement failures, Service Users need to reconcile reports immediately (within 3 working days) by updating the DDI status.

AUDDIS Implementation

AUDDIS is a service that must be applied for by the Service User.  Application forms are available from the sponsoring bank and should be completed and returned to the sponsoring bank.  Note:  A Service User may need to execute a new indemnity claim. In terms of application timescales, on average they are:


  1. 4 to 8 weeks

    to obtain a new SUN – 4 to 8 weeks

  2. Up to 12 weeks

    to transfer and existing SUN to be AUDDIS enabled – up to 12 weeks

AUDDIS Migration

Existing SUNs must undertake a ‘migration’ project. We would highly recommend getting outside help if you are planning to implement AUDDIS as it is usually a one off task for an organisation it is critical to future collections that you get it right.

This involves:

Box Icon Going live

Going live

Box Icon Reconciliation of failures

Reconciliation of failures

Box Icon Bacs testing

Bacs testing

Box Icon Registering of existing DDI's under AUDDIS (migration)

Registering of existing DDI's under AUDDIS (migration)

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