diff --git a/silkaj/tui.py b/silkaj/tui.py
index 9afc551dfefeedb6795d043aea992ff727d1d9d7..ecc407ac94d95ec245907d38cc2af7f27aa78629 100644
--- a/silkaj/tui.py
+++ b/silkaj/tui.py
@@ -14,6 +14,7 @@
 # along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
 
 import sys
+from typing import List, Optional
 
 import click
 
@@ -22,7 +23,9 @@ from silkaj import crypto_tools as ct
 from silkaj import wot_tools
 
 
-def display_amount(tx, message, amount, ud_value, currency_symbol):
+def display_amount(
+    tx: List, message: str, amount: float, ud_value: float, currency_symbol: str
+) -> None:
     """
     Displays an amount in unit and relative reference.
     """
@@ -36,7 +39,7 @@ def display_amount(tx, message, amount, ud_value, currency_symbol):
     )
 
 
-def display_pubkey(tx, message, pubkey):
+def display_pubkey(tx: List, message: str, pubkey: str) -> None:
     """
     Displays a pubkey and the eventually associated id.
     """
@@ -46,7 +49,11 @@ def display_pubkey(tx, message, pubkey):
         tx.append([f"{message} (id)", id["uid"]])
 
 
-def gen_pubkey_checksum(pubkey, short=False, length=constants.SHORT_PUBKEY_SIZE):
+def gen_pubkey_checksum(
+    pubkey: str,
+    short: Optional[bool] = False,
+    length: Optional[int] = constants.SHORT_PUBKEY_SIZE,
+) -> str:
     """
     Returns "<pubkey>:<checksum>" in full form.
     returns `length` first chars of pubkey and checksum in short form.
@@ -56,6 +63,6 @@ def gen_pubkey_checksum(pubkey, short=False, length=constants.SHORT_PUBKEY_SIZE)
     return f"{short_pubkey}:{ct.gen_checksum(pubkey)}"
 
 
-def send_doc_confirmation(document_name):
+def send_doc_confirmation(document_name: str) -> None:
     if not click.confirm(f"Do you confirm sending this {document_name}?"):
         sys.exit(constants.SUCCESS_EXIT_STATUS)