diff --git a/app.py b/app.py
index 5e2de3e..eb63cb9 100644
--- a/app.py
+++ b/app.py
@@ -24,6 +24,8 @@ file_handler.setFormatter(logging.Formatter('%(asctime)s %(levelname)s: %(messag
 app.logger.addHandler(file_handler)
 app.logger.setLevel(logging.INFO)
 
+msg_403_not_primary = "Only a PRIMARY device can perform this action"
+
 
 @app.route("/api/v1/login", methods=["POST"])
 def login():
@@ -69,5 +71,19 @@ def refresh_token():
 @jwt_required()
 def get_all_devices():
     if get_jwt()["typ"] != "PRIMARY":
-        return make_response(jsonify(msg="Only a PRIMARY device can list all devices"), 403)
+        return make_response(jsonify(msg=msg_403_not_primary), 403)
     return make_response(jsonify([d.to_dict() for d in db.get_all_devices(cur)]), 200)
+
+
+@app.route("/api/v1/sim-cards", methods=["GET"])
+@jwt_required()
+def get_sim_cards_by_device():
+    if not is_primary(get_jwt()):
+        return make_response(jsonify(msg=msg_403_not_primary), 403)
+
+    access_key = request.args.get('access_key', None)
+    return make_response(jsonify([s.to_dict() for s in db.get_sim_cards_by_device(cur, access_key)]), 200)
+
+
+def is_primary(jwt):
+    return jwt["typ"] == "PRIMARY"
diff --git a/db.py b/db.py
index a48acf7..22b24a1 100644
--- a/db.py
+++ b/db.py
@@ -1,4 +1,4 @@
-from dto import Device
+from dto import Device, SimCard
 
 
 def get_all_devices(cur) -> list[Device]:
@@ -10,3 +10,13 @@ def get_all_devices(cur) -> list[Device]:
         devices.append(Device.convert(item))
     return devices
 
+
+def get_sim_cards_by_device(cur, access_key: str) -> list[SimCard]:
+    if access_key is None or not access_key:
+        return []
+
+    sim_cards_from_db = cur.execute("SELECT phone_number, device_access_key FROM sim_cards WHERE device_access_key = ?", (access_key,)).fetchall()
+    sim_cards = []
+    for item in sim_cards_from_db:
+        sim_cards.append(SimCard.convert(item))
+    return sim_cards
diff --git a/dto.py b/dto.py
index 2ed4a19..a3a6edd 100644
--- a/dto.py
+++ b/dto.py
@@ -1,9 +1,10 @@
-class Device:
-    def __init__(self, access_key, device_type, name):
-        self.access_key = access_key
-        self.device_type = device_type
-        self.name = name
+from dataclasses import dataclass
 
+@dataclass
+class Device:
+    access_key: str
+    device_type: str
+    name: str
 
     def to_dict(self):
         return {
@@ -15,3 +16,16 @@ class Device:
     def convert(device_from_db) -> Device:
         return Device(*device_from_db)
 
+@dataclass
+class SimCard:
+    phone_number: str
+    device_access_key: str
+
+    def to_dict(self):
+        return {
+                'phone_number': self.phone_number,
+                'device_access_key': self.device_access_key
+               }
+
+    def convert(sim_from_db) -> SimCard:
+        return SimCard(*sim_from_db)
diff --git a/init-db.py b/init-db.py
index 014c594..144495c 100644
--- a/init-db.py
+++ b/init-db.py
@@ -14,7 +14,7 @@ cur = con.cursor()
 cur.execute("CREATE TABLE devices(access_key, secret_key_hash, type, name)")
 cur.execute("CREATE TABLE messages(content, ts_received, ts_sent, sender, recipient)")
 cur.execute("CREATE TABLE sim_events(sim_id, ts, note, cost, currency)")
-cur.execute("CREATE TABLE sim_cards(phone_number, device_id)")
+cur.execute("CREATE TABLE sim_cards(phone_number, device_access_key)")
 
 pw1_hash = flask_bcrypt.generate_password_hash('pw1').decode('utf-8')
 pw2_hash = flask_bcrypt.generate_password_hash('pw2').decode('utf-8')
@@ -24,6 +24,13 @@ cur.execute("""
     ('test_access_key2', ?, 'SECONDARY', 'test-secondary')
 """, (pw1_hash, pw2_hash))
 
+cur.execute("""
+    INSERT INTO sim_cards VALUES
+    ('+420123456789', 'test_access_key'),
+    ('+421000111222', 'test_access_key'),
+    ('+422999888777', 'test_access_key2')
+""")
+
 con.commit()
 con.close()