# Setting a notecard serial number "sn" remotely

**URL:** <https://discuss.blues.com/t/setting-a-notecard-serial-number-sn-remotely/174>\
**Category:** Notecard API\
**Created:** [March 18, 2021, 9:27pm UTC](https://discuss.blues.com/t/setting-a-notecard-serial-number-sn-remotely/174 "2021-03-18T21:27:43Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![RobLauer](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/roblauer/32/1567_2.png) [@RobLauer](https://discuss.blues.com/u/RobLauer)\
**Post date:** [March 18, 2021, 11:56pm UTC](https://discuss.blues.com/t/setting-a-notecard-serial-number-sn-remotely/174/2 "2021-03-18T23:56:56Z")

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Hi @Pat,

Yes, in fact you can use [environment variables](https://dev.blues.io/build/notecard-guides/understanding-environment-variables/) to set the “serial number” for a device.

Use `_sn` to override any previously-entered serial number.  
Use `_sn_default` to set it, but _not_ override the value if set already on the Notecard.

To access environment variables, look at the “Environment” tab when browsing device details:

 ![Screen Shot 2021-03-18 at 6.50.25 PM](https://us1.discourse-cdn.com/flex020/uploads/blues/original/1X/29e15481c2e6ea204c6f5b83123fc16d80e31314.png)

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