When viewing your Assessments, you may occasionally find that some of them have duplicate Reference Numbers:

This usually happens when a system user has entered the same Reference Prefix into more than one location:

To stop this happening in the future you can edit one of those locations to change the Reference Prefix:

1: Click Settings:

2: Next, click Users & Locations, and then click Location/User Management:

3: Now, click to highlight the Location you wish to alter and then click Edit Location:

4: In the Location Details window that pops up, you can alter the Reference Prefix:

This means that every assessment created in the future from this location will have the new prefix. However, it will not migrate any previous assessments to the new Reference Prefix. You will need to manually alter the Reference Number for each and every previous assessment created with the duplicate references.