# V3 signature validation doesn't work for space

**URL:** <https://community.hubspot.com/t/v3-signature-validation-doesnt-work-for-space/147604>\
**Category:** APIs & Integrations\
**Tags:** professional\
**Created:** [March 23, 2026, 11:36pm UTC](https://community.hubspot.com/t/v3-signature-validation-doesnt-work-for-space/147604 "2026-03-23T23:36:19Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![JZhao](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/jzhao/32/98997_2.png) [@JZhao](https://community.hubspot.com/u/JZhao)\
**Post date:** [March 23, 2026, 11:36pm UTC](https://community.hubspot.com/t/v3-signature-validation-doesnt-work-for-space/147604/1 "2026-03-23T23:36:19Z")

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I am following this link to implement v3 signature validation: [Validating Requests - HubSpot docs](https://developers.hubspot.com/docs/apps/developer-platform/build-apps/authentication/request-validation#validate-the-v3-request-signature)

The problem I am facing is that if the “x-hubspot-signature-v3” includes a space, the generated hashedString will have a plus sign. That will make the signature mismatch. For example, I got a signature:  
“X-HubSpot-Signature-v3”:“s9fg/l7gop54ZS/srjGtdZr4E Gn4LNDdUEFKy6/Dlo=”

The code crypto.createHmac(“sha256”, process.env.CLIENT\_SECRET).update(rawString).digest(“base64”) gives me “s9fg/l7gop54ZS/srjGtdZr4E+Gn4LNDdUEFKy6/Dlo=”.

As you can see the space is replaced by a “+” sign. How do I handle this case?

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<div class="post-metadata">

**Author:** ![STierney](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/stierney/32/186066_2.png) [@STierney](https://community.hubspot.com/u/STierney)\
**Post date:** [March 24, 2026, 12:23am UTC](https://community.hubspot.com/t/v3-signature-validation-doesnt-work-for-space/147604/2 "2026-03-24T00:23:03Z")

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Hey @JZhao,  
Thanks for posting in the Community!  
I’d like to tag in some experts to see what insight they may have on how to approach this use case. @Anton, @Teun, and @alyssamwilie - any thoughts here?  
Shane, Senior Community Moderator