What is a SUN?
A SUN is issued by BACS through your sponsoring bank and is used to identify your business when processing Direct Debit or Direct Credit transactions. It ensures all payments are traceable and compliant with the Direct Debit Guarantee.
📌Note: Your bank can withdraw your SUN if you fail to comply with scheme rules.
Why do you need a SUN?
To submit payment instructions directly to BACS.
To maintain control over your payment processes and improve cash flow.
To build trust with customers by appearing as the originator on their bank statements.
Eligibility requirements
Before applying, confirm that your business meets typical criteria:
A UK bank account with a sponsoring bank.
Ability to comply with Direct Debit scheme rules.
Sufficient financial reserves to cover refunds under the Direct Debit Guarantee.
Strong administrative processes to minimize errors and protect the scheme's integrity. (Some banks may require a minimum trading history and turnover, e.g., three years and £1m annual turnover.)
Steps to obtain a SUN
Contact your Relationship Manager at your bank.
Explain that you want to apply for a Service User Number for BACS payments.Request and complete the required forms.
These may include:Bacstel-IP application
AUDDIS and Paperless Direct Debit forms
Indemnity form
Submit the completed forms to your bank.
Your bank will review your application and forward it to their BACS team.Complete compliance checks and testing.
You may need to submit an AUDDIS test file to confirm readiness for paperless Direct Debit.
Receive your SUN.
Once approved, your bank will issue your six-digit Service User Number.
Typical timeframe: two–ten weeks, depending on the bank’s process.