> ## Documentation Index > Fetch the complete documentation index at: https://support.servicem8.com/llms.txt > Use this file to discover all available pages before exploring further. # Can I add a prefix or suffix to job numbers? > Find out whether you can add a prefix or suffix to job numbers in ServiceM8. Yes, it's possible to add a prefix or suffix to your auto-generated ServiceM8 job numbers e.g. 1234-A. You may find you need to add a prefix or suffix to your ServiceM8 job numbers if you encounter issues such as duplicate invoice numbers for ServiceM8 invoices synced to your connected accounting package. * Prefixes can contain letters, numbers, dashes and underscores . * Suffixes can contain letters, dashes and underscores. * You can have up to 4 characters total across prefixes and suffixes. Generally, this tool is not designed for frequent use, and ServiceM8 does not recommend adding a prefix/suffix relating to the year, specific jobs or job types, or specific clients, as they inevitably cause issues. **To set a Prefix or Suffix to your Job Numbers, login to your Online Dashboard and [click this link to start the Job Number Prefix/Suffix wizard](https://go.servicem8.com/help_me/SetJobNumberPrefixSuffix).** [](/images/002-444-676-70bb0110-d87a-4970-accd-33ab83e3317b.png)