diff --git a/.changeset/soft-eagles-relate.md b/.changeset/soft-eagles-relate.md
new file mode 100644
index 00000000..9bdcf15f
--- /dev/null
+++ b/.changeset/soft-eagles-relate.md
@@ -0,0 +1,5 @@
+---
+"@capacitor-firebase/authentication": patch
+---
+
+fix: `getIdToken` causes app crash if no user is signed in
diff --git a/packages/authentication/android/src/main/java/dev/robingenz/capacitorjs/plugins/firebase/authentication/FirebaseAuthentication.java b/packages/authentication/android/src/main/java/dev/robingenz/capacitorjs/plugins/firebase/authentication/FirebaseAuthentication.java
index 9ff6f66c..07979b4e 100644
--- a/packages/authentication/android/src/main/java/dev/robingenz/capacitorjs/plugins/firebase/authentication/FirebaseAuthentication.java
+++ b/packages/authentication/android/src/main/java/dev/robingenz/capacitorjs/plugins/firebase/authentication/FirebaseAuthentication.java
@@ -130,6 +130,10 @@ public FirebaseUser getCurrentUser() {
 
     public void getIdToken(Boolean forceRefresh, final GetIdTokenResultCallback resultCallback) {
         FirebaseUser user = getCurrentUser();
+        if (user == null) {
+            resultCallback.error(FirebaseAuthenticationPlugin.ERROR_NO_USER_SIGNED_IN);
+            return;
+        }
         Task<GetTokenResult> tokenResultTask = user.getIdToken(forceRefresh);
         tokenResultTask.addOnCompleteListener(
             task -> {
diff --git a/packages/authentication/ios/Plugin/FirebaseAuthentication.swift b/packages/authentication/ios/Plugin/FirebaseAuthentication.swift
index c32c7963..0691e6f7 100644
--- a/packages/authentication/ios/Plugin/FirebaseAuthentication.swift
+++ b/packages/authentication/ios/Plugin/FirebaseAuthentication.swift
@@ -75,11 +75,14 @@ public typealias AuthStateChangedObserver = () -> Void
         return Auth.auth().currentUser
     }
 
-    @objc func getIdToken(_ forceRefresh: Bool, completion: @escaping (String?, Error?) -> Void) {
-        let user = self.getCurrentUser()
-        user?.getIDTokenResult(forcingRefresh: forceRefresh, completion: { result, error in
+    @objc func getIdToken(_ forceRefresh: Bool, completion: @escaping (String?, String?) -> Void) {
+        guard let user = self.getCurrentUser() else {
+            completion(nil, self.plugin.errorNoUserSignedIn)
+            return
+        }
+        user.getIDTokenResult(forcingRefresh: forceRefresh, completion: { result, error in
             if let error = error {
-                completion(nil, error)
+                completion(nil, error.localizedDescription)
                 return
             }
             completion(result?.token, nil)
diff --git a/packages/authentication/ios/Plugin/FirebaseAuthenticationPlugin.swift b/packages/authentication/ios/Plugin/FirebaseAuthenticationPlugin.swift
index 51e5ed92..3dc42719 100644
--- a/packages/authentication/ios/Plugin/FirebaseAuthenticationPlugin.swift
+++ b/packages/authentication/ios/Plugin/FirebaseAuthenticationPlugin.swift
@@ -83,9 +83,9 @@ public class FirebaseAuthenticationPlugin: CAPPlugin {
     @objc func getIdToken(_ call: CAPPluginCall) {
         let forceRefresh = call.getBool("forceRefresh", false)
 
-        implementation?.getIdToken(forceRefresh, completion: { token, error in
-            if let error = error {
-                call.reject(error.localizedDescription)
+        implementation?.getIdToken(forceRefresh, completion: { token, errorMessage in
+            if let errorMessage = errorMessage {
+                call.reject(errorMessage)
                 return
             }
             var result = JSObject()
diff --git a/packages/authentication/src/web.ts b/packages/authentication/src/web.ts
index a02ade13..d6c0418f 100644
--- a/packages/authentication/src/web.ts
+++ b/packages/authentication/src/web.ts
@@ -90,7 +90,10 @@ export class FirebaseAuthenticationWeb
 
   public async getIdToken(): Promise<GetIdTokenResult> {
     const auth = getAuth();
-    const idToken = await auth.currentUser?.getIdToken();
+    if (!auth.currentUser) {
+      throw new Error(FirebaseAuthenticationWeb.ERROR_NO_USER_SIGNED_IN);
+    }
+    const idToken = await auth.currentUser.getIdToken();
     const result: GetIdTokenResult = {
       token: idToken || '',
     };