diff --git a/FuelBoard/ContentView.swift b/FuelBoard/ContentView.swift
index 1fca183..07f98ae 100644
--- a/FuelBoard/ContentView.swift
+++ b/FuelBoard/ContentView.swift
@@ -321,7 +321,7 @@ struct ContentView: View {
 #else
             let shouldSkipOnboarding = false
 #endif
-            if FuelStore.loadHasCompletedOnboarding()
+            if !FuelStore.shouldShowOnboarding()
                 || shouldSkipOnboarding {
                 locationManager.startForegroundTracking()
                 // Geofences and the Live Activity must follow the user even in
diff --git a/FuelBoardTests/Tests/FuelBoardSharedTests/FuelBoardTests.swift b/FuelBoardTests/Tests/FuelBoardSharedTests/FuelBoardTests.swift
index d16c7b5..86047a8 100644
--- a/FuelBoardTests/Tests/FuelBoardSharedTests/FuelBoardTests.swift
+++ b/FuelBoardTests/Tests/FuelBoardSharedTests/FuelBoardTests.swift
@@ -671,3 +671,15 @@ final class RoadDistanceCacheTests: XCTestCase {
         XCTAssertEqual(km, s.distanceKM(to: 51.6, lng2: -0.1), accuracy: 0.0001)
     }
 }
+
+// MARK: - Install identity
+
+final class InstallIdentityTests: XCTestCase {
+    func testFreshInstallIsStableAfterFirstCall() {
+        // The first call seeds the common install id (local == keychain), so
+        // any subsequent call in the same process must report NOT-fresh. This
+        // holds regardless of persisted keychain/defaults state from prior runs.
+        _ = FuelStore.isFreshInstall()
+        XCTAssertFalse(FuelStore.isFreshInstall())
+    }
+}
diff --git a/Shared/FuelStore.swift b/Shared/FuelStore.swift
index eccb247..33f354c 100644
--- a/Shared/FuelStore.swift
+++ b/Shared/FuelStore.swift
@@ -949,6 +949,43 @@ struct FuelStore {
         saveString(completed ? "1" : "0", service: onboardingCompletedKey)
     }
 
+    // MARK: Install identity — distinguish a genuinely fresh install (where
+    // onboarding should replay) from later launches of the same install.
+
+    /// Keychain copy of the install id (survives reinstall).
+    private static let installIDKey = "fuelboard.installID"
+    /// Local (app-own container) copy — wiped on reinstall, persists across
+    /// normal launches. Free SideStore accounts have no app-group container,
+    /// so this app-own defaults domain is the reliable "same install" signal.
+    private static let localInstallIDKey = "fuelboard.installID.local"
+
+    /// True when this is a first-ever install OR the app was just reinstalled
+    /// (local install id missing/different from the keychain id). Seeds a fresh
+    /// id into both stores so the next launch within the same install is not a
+    /// "fresh install" any more.
+    static func isFreshInstall() -> Bool {
+        let local = UserDefaults.standard.string(forKey: localInstallIDKey)
+        let remote = loadString(service: installIDKey)
+        if let local, let remote, local == remote { return false }
+        // Fresh / mismatched install (or first launch). Pattern a common id so
+        // subsequent launches of this install are recognised as the same one.
+        let id = UUID().uuidString
+        UserDefaults.standard.set(id, forKey: localInstallIDKey)
+        saveString(id, service: installIDKey)
+        return true
+    }
+
+    /// Onboarding should present when it hasn't been completed in this install
+    /// OR this is a freshly-installed app (so the walkthrough replays on a new
+    /// install, e.g. after a SideStore reinstall, without re-showing on every
+    /// ordinary launch). The install check always runs (it seeds the id) rather
+    /// than short-circuiting, so a brand-new install is recorded before the
+    /// user ever fills in onboarding.
+    static func shouldShowOnboarding() -> Bool {
+        let fresh = isFreshInstall()
+        return !loadHasCompletedOnboarding() || fresh
+    }
+
     // MARK: Road distances (Apple-Maps-matched, computed by the app)
 
     /// Cached road/routed distances (metres) keyed by station ID, computed by