diff --git a/src/apps/nem/multisig.py b/src/apps/nem/multisig.py
index 1058cfd8e..c3e51383f 100644
--- a/src/apps/nem/multisig.py
+++ b/src/apps/nem/multisig.py
@@ -6,8 +6,12 @@ from trezor.crypto import nem
 
 
 async def ask_multisig(ctx, msg: NEMSignTx):
-    # todo
-    await require_confirm_action(ctx, 'Multisig?')
+    address = nem.compute_address(msg.multisig.signer, msg.transaction.network)
+    if msg.cosigning:
+        await require_confirm_address(ctx, 'Cosign transaction for', address)
+    else:
+        await require_confirm_address(ctx, 'Initiate transaction for', address)
+    await require_confirm_fee(ctx, 'Confirm multisig fee', msg.multisig.fee)
 
 
 async def ask_aggregate_modification(ctx, msg: NEMSignTx):
@@ -38,8 +42,10 @@ def serialize_multisig(msg: NEMTransactionCommon, public_key: bytes, inner: byte
     return w
 
 
-def serialize_multisig_signature(msg: NEMTransactionCommon, public_key: bytes, inner: bytes, address: str):
-    w = write_common(msg, bytearray(public_key), NEM_TRANSACTION_TYPE_MULTISIG_SIGNATURE)
+def serialize_multisig_signature(common: NEMTransactionCommon, public_key: bytes,
+                                 inner: bytes, address_public_key: bytes):
+    address = nem.compute_address(address_public_key, common.network)
+    w = write_common(common, bytearray(public_key), NEM_TRANSACTION_TYPE_MULTISIG_SIGNATURE)
     digest = hashlib.sha3_256(inner).digest(True)
 
     write_uint32(w, 4 + len(digest))
diff --git a/src/apps/nem/signing.py b/src/apps/nem/signing.py
index f56f52857..7ff52a596 100644
--- a/src/apps/nem/signing.py
+++ b/src/apps/nem/signing.py
@@ -16,6 +16,7 @@ async def sign_tx(ctx, msg: NEMSignTx):
 
     if msg.multisig:
         public_key = msg.multisig.signer
+        await ask_multisig(ctx, msg)
     else:
         public_key = _get_public_key(node)
 
@@ -35,6 +36,10 @@ async def sign_tx(ctx, msg: NEMSignTx):
     else:
         raise ValueError('No transaction provided')
 
+    if msg.multisig:
+        # wrap transaction in multisig wrapper
+        tx = _multisig(node, msg, tx)
+
     signature = ed25519.sign(node.private_key(), tx, helpers.NEM_HASH_ALG)
 
     resp = NEMSignedTx()
@@ -43,6 +48,16 @@ async def sign_tx(ctx, msg: NEMSignTx):
     return resp
 
 
+def _multisig(node, msg: NEMSignTx, inner_tx: bytes) -> bytes:
+    if msg.cosigning:
+        return serialize_multisig_signature(msg.multisig,
+                                            _get_public_key(node),
+                                            inner_tx,
+                                            msg.multisig.signer)
+    else:
+        return serialize_multisig(msg.multisig, _get_public_key(node), inner_tx)
+
+
 def _get_public_key(node) -> bytes:
     # 0x01 prefix is not part of the actual public key, hence removed
     return node.public_key()[1:]
@@ -75,10 +90,7 @@ async def _supply_change(ctx, public_key: bytes, msg: NEMSignTx):
 
 async def _aggregate_modification(ctx, public_key: bytes, msg: NEMSignTx):
     await ask_aggregate_modification(ctx, msg)
-    if not msg.multisig:
-        w = serialize_aggregate_modification(msg, public_key)
-    else:
-        w = bytearray()  # todo
+    w = serialize_aggregate_modification(msg, public_key)
 
     for m in msg.aggregate_modification.modifications:
         serialize_cosignatory_modification(w, m.type, m.public_key)
diff --git a/tests/test_apps.nem.multisig.py b/tests/test_apps.nem.multisig.py
index caa3da37a..e816e6062 100644
--- a/tests/test_apps.nem.multisig.py
+++ b/tests/test_apps.nem.multisig.py
@@ -29,12 +29,12 @@ class TestNemMultisig(unittest.TestCase):
 
         self.assertEqual(multisig, unhexlify("0410000001000098df1a3c002000000059d89076964742ef2a2089d26a5aa1d2c7a7bb052a46c1de159891e91ad3d76e808d5b00000000003f6f3c006c0000000110000001000098df1a3c0020000000abac2ee3d4aaa7a3bfb65261a00cc04c761521527dd3f2cf741e2815cbba83ac0024f400000000003f6f3c0001000000280000000200000020000000e6cff9b3725a91f31089c3acca0fac3e341c00b1c8c6e9578f66c4514509c3b3"))
 
-        address = "TCRXYUQIMFA7AOGL5LF3YWLC7VABLYUMJ5ACBUNL"
+        address_pubkey = unhexlify("abac2ee3d4aaa7a3bfb65261a00cc04c761521527dd3f2cf741e2815cbba83ac")
         m = _create_common_msg(NEM_NETWORK_TESTNET,
                                3939891,
                                6000000,
                                3961491)
-        multisig = serialize_multisig_signature(m, unhexlify("71cba4f2a28fd19f902ba40e9937994154d9eeaad0631d25d525ec37922567d4"), base_tx, address)
+        multisig = serialize_multisig_signature(m, unhexlify("71cba4f2a28fd19f902ba40e9937994154d9eeaad0631d25d525ec37922567d4"), base_tx, address_pubkey)
 
         self.assertEqual(multisig, unhexlify("0210000001000098331e3c002000000071cba4f2a28fd19f902ba40e9937994154d9eeaad0631d25d525ec37922567d4808d5b000000000093723c0024000000200000008ec165580bdabfd31ce6007a1748ce5bdf30eab7a214743097de3bc822ac7e002800000054435258595551494d464137414f474c354c463359574c43375641424c59554d4a35414342554e4c"))
 
@@ -62,16 +62,15 @@ class TestNemMultisig(unittest.TestCase):
                                59414342,
                                6000000,
                                59500742)
-        address = "NDDRG3UEB5LZZZMDWBE4RTKZK73JBHPAIWBHCFMV"
-        multisig = serialize_multisig_signature(m, unhexlify("1b49b80203007117d034e45234ffcdf402c044aeef6dbb06351f346ca892bce2"), base_tx, address)
+        address_pubkey = unhexlify("a1df5306355766bd2f9a64efdc089eb294be265987b3359093ae474c051d7d5a")
+        multisig = serialize_multisig_signature(m, unhexlify("1b49b80203007117d034e45234ffcdf402c044aeef6dbb06351f346ca892bce2"), base_tx, address_pubkey)
         self.assertEqual(multisig, unhexlify("021000000100006846978a03200000001b49b80203007117d034e45234ffcdf402c044aeef6dbb06351f346ca892bce2808d5b0000000000c6e88b032400000020000000bfa2088f7720f89dd4664d650e321dabd02fab61b7355bc88a391a848a49786a280000004e4444524733554542354c5a5a5a4d445742453452544b5a4b37334a424850414957424843464d56"))
 
         m = _create_common_msg(NEM_NETWORK_MAINNET,
                                59414381,
                                6000000,
                                59500781)
-        address = "NDDRG3UEB5LZZZMDWBE4RTKZK73JBHPAIWBHCFMV"
-        multisig = serialize_multisig_signature(m, unhexlify("7ba4b39209f1b9846b098fe43f74381e43cb2882ccde780f558a63355840aa87"), base_tx, address)
+        multisig = serialize_multisig_signature(m, unhexlify("7ba4b39209f1b9846b098fe43f74381e43cb2882ccde780f558a63355840aa87"), base_tx, address_pubkey)
         self.assertEqual(multisig, unhexlify("02100000010000686d978a03200000007ba4b39209f1b9846b098fe43f74381e43cb2882ccde780f558a63355840aa87808d5b0000000000ede88b032400000020000000bfa2088f7720f89dd4664d650e321dabd02fab61b7355bc88a391a848a49786a280000004e4444524733554542354c5a5a5a4d445742453452544b5a4b37334a424850414957424843464d56"))