diff --git a/.env.example b/.env.example
index 1b3649f..4f2a40e 100644
--- a/.env.example
+++ b/.env.example
@@ -26,6 +26,11 @@
 # Leave off in production; the routes expose per-device state to any accepted JWT.
 # DEBUG_ENDPOINT=false
 
+# Appended as " (<label>)" to every SMS and push body, so a recipient can tell
+# which server sent it. NODE_ENV cannot do this: the Docker image sets it to
+# "production" everywhere. Unset or blank appends nothing.
+# MESSAGE_ENV_LABEL=test
+
 # --- SMS notifications (/notify-sms) ---
 
 # Master switch. While false, every /notify-sms route returns 503 SMS_DISABLED
@@ -75,8 +80,3 @@
 # sms_blocked_numbers table that the STOP webhook writes to. Normalized before
 # comparison, so formatting does not defeat them.
 # SMS_BLOCKED_NUMBERS=+15555550123,+15555550124
-
-# Appended as " (<label>)" to every SMS and push body, so a recipient can tell
-# which server sent it. NODE_ENV cannot do this: the Docker image sets it to
-# "production" everywhere. Unset or blank appends nothing.
-# SMS_ENV_LABEL=test
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 636497d..e246e1b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,9 +8,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 ### Added
-- Optional `SMS_ENV_LABEL` appends ` (<label>)` to every SMS and push body, so a recipient can tell which server sent it; unset or blank appends nothing. `NODE_ENV` cannot serve, since the Docker image sets it to `production` on every server.
+- Optional `MESSAGE_ENV_LABEL` appends ` (<label>)` to every SMS and push body, so a recipient can tell which server sent it; unset or blank appends nothing. `NODE_ENV` cannot serve, since the Docker image sets it to `production` on every server.
 ### Changed in DB or environment
-- `SMS_ENV_LABEL` (see above) on test environment
+- `MESSAGE_ENV_LABEL` (see above) on test environment
+
 
 ## [0.2.4] - 2026.10.13
 ### Changed
diff --git a/README.md b/README.md
index 5ef9376..2019620 100644
--- a/README.md
+++ b/README.md
@@ -738,7 +738,7 @@ Set `NOTIFY_DATA_DIR` to a durable directory, or keep the Docker default `/app/d
 | `FIREBASE_SERVICE_ACCOUNT_JSON` **or** working ADC | **Required** for FCM (wakeup and AlertSearch) | ADC if JSON unset |
 | `NOTIFY_DATA_DIR` | **Durable** path (or volume on `/app/data`) | `./data` (cwd-relative; in Docker that is `/app/data`) |
 | `NODE_ENV` | Must **not** be `test-local` (that bypasses ethr JWT expiry) | Docker image sets `production` |
-| `SMS_ENV_LABEL` | Optional; appended as ` (<label>)` to every SMS and push body. Leave unset in production, set it (e.g. `test`) elsewhere | Unset (nothing appended) |
+| `MESSAGE_ENV_LABEL` | Optional; appended as ` (<label>)` to every SMS and push body. Leave unset in production, set it (e.g. `test`) elsewhere | Unset (nothing appended) |
 | `SMS_ENABLED` | Optional; `/notify-sms` returns `503 SMS_DISABLED` while off | `false` |
 | `SMS_CODE_SECRET` | **Required** when `SMS_ENABLED` (startup fails without it) | None |
 | `TWILIO_ACCOUNT_SID`, `TWILIO_AUTH_TOKEN` | **Required** to send; absent means `SMS_NOT_CONFIGURED` per send | None |
diff --git a/src/env.ts b/src/env.ts
index d74987e..2730017 100644
--- a/src/env.ts
+++ b/src/env.ts
@@ -67,12 +67,12 @@ function stringEnv(name: string): string | undefined {
 }
 
 /**
- * Appends " (<SMS_ENV_LABEL>)" to user-visible text, so a recipient can tell
+ * Appends " (<MESSAGE_ENV_LABEL>)" to user-visible text, so a recipient can tell
  * which deployment sent it. NODE_ENV cannot serve: the Docker image fixes it to
  * "production" on every server. Read per call, like smsConfig.
  */
 export function withEnvLabel(text: string): string {
-  const label = process.env.SMS_ENV_LABEL?.trim();
+  const label = process.env.MESSAGE_ENV_LABEL?.trim();
   return label ? `${text} (${label})` : text;
 }
 
diff --git a/test/env.test.ts b/test/env.test.ts
index a60b94b..2495f87 100644
--- a/test/env.test.ts
+++ b/test/env.test.ts
@@ -5,7 +5,7 @@ import { smsConfig, withEnvLabel } from "../src/env.js";
 const KEYS = [
   "SMS_ENABLED",
   "SMS_REQUIRE_ACTION_CLAIM",
-  "SMS_ENV_LABEL",
+  "MESSAGE_ENV_LABEL",
 ] as const;
 
 const saved: Record<string, string | undefined> = {};
@@ -66,12 +66,12 @@ describe("smsConfig boolean flags", () => {
 describe("withEnvLabel", () => {
   it("leaves the text alone when unset or blank", () => {
     assert.equal(withEnvLabel("hi"), "hi");
-    process.env.SMS_ENV_LABEL = "  ";
+    process.env.MESSAGE_ENV_LABEL = "  ";
     assert.equal(withEnvLabel("hi"), "hi");
   });
 
   it("appends the trimmed label in parentheses", () => {
-    process.env.SMS_ENV_LABEL = " test ";
+    process.env.MESSAGE_ENV_LABEL = " test ";
     assert.equal(withEnvLabel("hi"), "hi (test)");
   });
 });