# What level is the TLS handshake done at?

**URL:** <https://developer.community.nhs.uk/t/what-level-is-the-tls-handshake-done-at/8745>\
**Category:** FAQ-Troubleshooting\
**Tags:** nrl-api\
**Created:** [12 November 2025 14:49 UTC](https://developer.community.nhs.uk/t/what-level-is-the-tls-handshake-done-at/8745 "2025-11-12T14:49:09Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Elizabeth\_Williams](https://dub1.discourse-cdn.com/nhsdigitaldeveloper/user_avatar/developer.community.nhs.uk/elizabeth_williams/32/755_2.png) [@Elizabeth\_Williams](https://developer.community.nhs.uk/u/Elizabeth_Williams)\
**Post date:** [12 November 2025 14:49 UTC](https://developer.community.nhs.uk/t/what-level-is-the-tls-handshake-done-at/8745/1 "2025-11-12T14:49:09Z")

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Does the TLS handshake need to be done on an infrastructure level, or an application level?

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<div class="post-metadata">

**Author:** ![Elizabeth\_Williams](https://dub1.discourse-cdn.com/nhsdigitaldeveloper/user_avatar/developer.community.nhs.uk/elizabeth_williams/32/755_2.png) [@Elizabeth\_Williams](https://developer.community.nhs.uk/u/Elizabeth_Williams)\
**Post date:** [12 November 2025 14:49 UTC](https://developer.community.nhs.uk/t/what-level-is-the-tls-handshake-done-at/8745/2 "2025-11-12T14:49:26Z")

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The TLS handshake happens before any request, it happens at the infrastructure layer. You can do extra checks at the application layer if you want but once it reaches the application the mTLS handshake must have already happened. For more general information about mTLS we recommend looking at some online resources like: [https://www.cloudflare.com/learning/access-management/what-is-mutual-tls/](https://www.cloudflare.com/learning/access-management/what-is-mutual-tls/)