diff --git a/.env.example b/.env.example
index f51f3f2..ca5be35 100644
--- a/.env.example
+++ b/.env.example
@@ -22,6 +22,11 @@ EVOSCIENTIST_WORKSPACE_DIR=
 # when the backend was started manually (no deploy sidecar); otherwise the
 # sidecar value wins. Defaults to a uuid derived from the workspace root.
 EVOSCIENTIST_DEPLOYMENT_ID=
+# Usage-attribution deployment id, matching the backend's
+# EVOSCIENTIST_USAGE_DEPLOYMENT_ID (stored in <data-dir>/deployment-id). This is
+# intentionally separate from the scope deployment id above so the usage
+# identity cannot repartition workspace scopes.
+EVOSCIENTIST_USAGE_DEPLOYMENT_ID=
 # Optional for local processes running as the same OS user: both sides share
 # ~/.config/evoscientist/provider-admin-token automatically. Set this explicitly
 # when the WebUI and backend run on different hosts, users, or containers.
diff --git a/src/app/api/usage/routes.test.ts b/src/app/api/usage/routes.test.ts
index 860fdfd..28797fc 100644
--- a/src/app/api/usage/routes.test.ts
+++ b/src/app/api/usage/routes.test.ts
@@ -8,7 +8,7 @@ vi.mock("server-only", () => ({}));
 const dataDir = fs.mkdtempSync(path.join(os.tmpdir(), "evosci-usage-routes-"));
 process.env.EVOSCIENTIST_DATA_DIR = dataDir;
 process.env.EVOSCIENTIST_USAGE_SINK_TOKEN = "route-test-token";
-process.env.EVOSCIENTIST_DEPLOYMENT_ID = "11111111-1111-4111-8111-111111111111";
+process.env.EVOSCIENTIST_USAGE_DEPLOYMENT_ID = "11111111-1111-4111-8111-111111111111";
 process.env.EVOSCIENTIST_WORKSPACE_ID = "ws1_fixture";
 
 const capabilities = await import("./capabilities/route");
diff --git a/src/lib/server/usageStore.test.ts b/src/lib/server/usageStore.test.ts
index eb92ede..388da1e 100644
--- a/src/lib/server/usageStore.test.ts
+++ b/src/lib/server/usageStore.test.ts
@@ -8,7 +8,7 @@ vi.mock("server-only", () => ({}));
 
 const dataDir = fs.mkdtempSync(path.join(os.tmpdir(), "evosci-usage-store-"));
 process.env.EVOSCIENTIST_DATA_DIR = dataDir;
-process.env.EVOSCIENTIST_DEPLOYMENT_ID = "11111111-1111-4111-8111-111111111111";
+process.env.EVOSCIENTIST_USAGE_DEPLOYMENT_ID = "11111111-1111-4111-8111-111111111111";
 process.env.EVOSCIENTIST_WORKSPACE_ID = "ws1_fixture";
 
 const store = await import("./usageStore");
diff --git a/src/lib/server/usageStore.ts b/src/lib/server/usageStore.ts
index 84fda0f..308e94d 100644
--- a/src/lib/server/usageStore.ts
+++ b/src/lib/server/usageStore.ts
@@ -574,7 +574,7 @@ export function usageStatus(filters: URLSearchParams): UsageStatusResult {
   const db = usageDb();
   const statusFilters = new URLSearchParams();
   for (const [key, environment] of [
-    ["deployment_id", "EVOSCIENTIST_DEPLOYMENT_ID"],
+    ["deployment_id", "EVOSCIENTIST_USAGE_DEPLOYMENT_ID"],
     ["workspace_id", "EVOSCIENTIST_WORKSPACE_ID"],
   ] as const) {
     const value = filters.get(key) ?? process.env[environment]?.trim();