ACC45 Claim Number Format

What is it?

The ACC45 claim number is the primary identifier that is used to lodge claims with ACC.

The current format of ACC claim numbers has 7 characters comprised of 1-2 letters, followed by 5-6 numbers (e.g. A999999, or AA99999). The current pool of available claim numbers is reaching the end in the current format, in readiness for this, we have made some changes to the ACC45 claim number format.


The new format has been defined as:

  • Five numbers followed by two letters - 99999AA , or
  • Four numbers followed by three letters - 9999AAA 

The existing ACC45 number format will continue to be accepted. This means that your systems will need to be able to use both number formats.

What are the benefits?

The ACC45 Claim Number is essential to caring for our clients and is the fundamental piece of information used externally to enable lodgement of a claim, submission of an invoice, searching for information etc.

Dates of importance

We previously reached out to all Practice Management System Software Vendors in April this year to understand your ability to support the change. If there are any changes to this timeline, or further information required, please let us know.

ACC are in the process of confirming when we will go live with the new format. The current indication is mid to late 2024, this will be shared once official.

What is the status / current status?

Supporting Practice Management System Software Vendors have their products ready to support the new format.

Latest communications

Visit the Developer Communications page to review the latest information sent about the ACC45 Claim Number Format change: Developer Resource Centre | Developer Comms

Read the following article on acc.co.nz: ACC45 number change

Tools / Resources

Before reaching out, review the support page through Developer Resource Centre | Support Expectations 

For detailed release notes on the specific APIs, visit Developer Resource Centre | Release Notes

For general API related questions refer to Developer Resource Centre | Frequently Asked Questions