diff --git a/.env.example b/.env.example
index 0005541..ec15807 100644
--- a/.env.example
+++ b/.env.example
@@ -7,7 +7,7 @@ CORS_ORIGINS=https://your-approved-web-origin.example
 DATA_DIR=/data
 # Required in production; generate at least 32 random characters outside this file.
 SESSION_SECRET=
-# Optional first-run admin bootstrap. Remove both immediately after provisioning.
+# Mandatory for first-run administrator provisioning. Remove both after bootstrap.
 BOOTSTRAP_ADMIN_EMAIL=
 BOOTSTRAP_ADMIN_PASSWORD=
 # Hard safety default; this release has no delivery capability.
diff --git a/README.md b/README.md
index c75cd84..6cf0bb5 100644
--- a/README.md
+++ b/README.md
@@ -74,7 +74,7 @@ curl -fsS http://localhost:8080/healthz
 docker compose down
 ```
 
-Compose passes the optional `BOOTSTRAP_ADMIN_EMAIL` and `BOOTSTRAP_ADMIN_PASSWORD` values to the API. Set both in an untracked `.env` only when provisioning a fresh instance, then remove them and rotate the password after the bootstrap admin is created. No credentials belong in this repository.
+Compose passes the one-time `BOOTSTRAP_ADMIN_EMAIL` and `BOOTSTRAP_ADMIN_PASSWORD` values to the API. **Set both before the first startup to create the initial administrator**; if both are blank, no login account is created. Use them only for a fresh instance, then remove them and rotate the password after the bootstrap admin is created. No credentials belong in this repository.
 
 Authenticated browser requests use a server-side session cookie; login creates a session and logout invalidates it. The liveness endpoints (`GET /api/v1/health/live` and `GET /healthz`) intentionally remain unauthenticated so Docker, ingress, and monitoring health checks can use them. Authentication is not a substitute for tenant/authorization checks: protected routes must enforce the session and organization boundary server-side.
 
diff --git a/docs/DEPLOYMENT.md b/docs/DEPLOYMENT.md
index 32ed9ab..bc97518 100644
--- a/docs/DEPLOYMENT.md
+++ b/docs/DEPLOYMENT.md
@@ -1,5 +1,18 @@
 # Portable deployment and recovery runbook (Phase 15)
 
+## Initial administrator is mandatory
+
+Before the **first** API startup, you must choose one administrator-provisioning method. The simplest method is to set both values in the untracked `.env` file:
+
+```dotenv
+BOOTSTRAP_ADMIN_EMAIL=admin@example.com
+BOOTSTRAP_ADMIN_PASSWORD=<strong-temporary-password>
+```
+
+These are not application defaults; they are one-time provisioning inputs. If both values are blank, the API starts without creating an administrator and login cannot succeed. Existing users are never overwritten by changing these values later.
+
+After the first successful login, remove both values from `.env`, restart the API, and rotate the administrator password through the supported account-management process. Never commit or share the password.
+
 ## Configuration
 
 Copy `.env.example` to an untracked deployment environment file. Production requires a secret-manager supplied `SESSION_SECRET` of at least 32 characters and refuses `AUTOMATED_OUTREACH_ENABLED=true`. Keep bootstrap credentials one-time only; remove and rotate them after provisioning. Never place secrets in images, Compose YAML, logs, backups, or public web roots.