<!--
{
  "availability" : [
    "iOS: 26.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "TelephonyMessagingKit",
  "identifier" : "/documentation/TelephonyMessagingKit/MMSPartContent/addCustomHeader(_:)",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
      "TelephonyMessagingKit"
    ],
    "preciseIdentifier" : "s:21TelephonyMessagingKit14MMSPartContentV15addCustomHeaderyyAC09MMSCustomH0VF"
  },
  "title" : "addCustomHeader(_:)"
}
-->

# addCustomHeader(_:)

A helper function to add custom headers.

```
mutating func addCustomHeader(_ header: MMSPartContent.MMSCustomHeader)
```

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)