> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://sensorpro.crisp.help/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# Mass update contacts

1 Create a segment called **massupdate**

2 Select `Segment rules` then `Custom` and select `Create a custom list (simple)` then press OK.

![](https://storage.crisp.chat/users/helpdesk/website/d9bed6c97dcdc000/yahoo-seg1_kie5tq.png)

3 Complete the form as shown below and click OK. 
| Change the selection crtieria to suit; note the asterisks act as wildcards.

![](https://storage.crisp.chat/users/helpdesk/website/d9bed6c97dcdc000/screenshot-2024-04-17-at-15511_1iwxi2e.png)

4 Press OK then click the Green arrow to build the segment.

5 After build is complete, click the view icon to confirm the contacts match your criteria

6 Click the *Action* icon ☰ and select the Mass change option for your purpose eg tag, opt-out etc

7 Verify the action completed by repeating Step 5 and view any contact record in this segment.