diff --git a/vertica_python/vertica/connection.py b/vertica_python/vertica/connection.py
index 0d0e6a54..d99deda0 100644
--- a/vertica_python/vertica/connection.py
+++ b/vertica_python/vertica/connection.py
@@ -49,6 +49,7 @@
 import signal
 import select
 import sys
+import unicodedata
 from collections import deque
 from struct import unpack
 
@@ -88,6 +89,53 @@
     warnings.warn(f"Cannot get the login user name: {str(e)}")
 
 
+# TOTP validation utilities (client-side)
+class TotpValidationResult(NamedTuple):
+    ok: bool
+    code: str
+    message: str
+
+
+INVALID_TOTP_MSG = 'Invalid TOTP: Please enter a valid 6-digit numeric code.'
+
+
+def validate_totp_code(raw_code: str, totp_is_valid=None) -> TotpValidationResult:
+    """Validate and normalize a user-supplied TOTP value.
+
+    Precedence:
+    1) Trim & normalize input (strip spaces and separators; normalize full-width digits)
+    2) Check emptiness, length == 6, and numeric-only
+
+    Returns TotpValidationResult(ok, code, message).
+    - Success: `ok=True`, `code` is a 6-digit ASCII string, `message=''`.
+    - Failure: `ok=False`, `code=''`, `message` is always the generic INVALID_TOTP_MSG.
+    `totp_is_valid` is reserved for optional server-side checks and ignored here.
+    """
+    try:
+        s = raw_code if raw_code is not None else ''
+        # Normalize Unicode (convert full-width digits etc. to ASCII)
+        s = unicodedata.normalize('NFKC', s)
+        # Strip leading/trailing whitespace
+        s = s.strip()
+        # Remove common separators inside the code
+        # Spaces, hyphens, underscores, dots, and common dash-like characters
+        separators = {' ', '\t', '\n', '\r', '\f', '\v', '-', '_', '.',
+                      '\u2012', '\u2013', '\u2014', '\u2212', '\u00B7', '\u2027', '\u30FB'}
+        # Replace all occurrences of separators
+        for sep in list(separators):
+            s = s.replace(sep, '')
+
+        # Empty / length / numeric checks
+        if s == '' or len(s) != 6 or not s.isdigit():
+            return TotpValidationResult(False, '', INVALID_TOTP_MSG)
+
+        # All good
+        return TotpValidationResult(True, s, '')
+    except Exception:
+        # Fallback generic error
+        return TotpValidationResult(False, '', INVALID_TOTP_MSG)
+
+
 def connect(**kwargs: Any) -> Connection:
     """Opens a new connection to a Vertica database."""
     return Connection(kwargs)
@@ -313,6 +361,14 @@ def __init__(self, options: Optional[Dict[str, Any]] = None) -> None:
         if self.totp is not None:
             if not isinstance(self.totp, str):
                 raise TypeError('The value of connection option "totp" should be a string')
+            # Validate using local validator
+            result = validate_totp_code(self.totp, totp_is_valid=None)
+            if not result.ok:
+                msg = result.message or INVALID_TOTP_MSG
+                self._logger.error(f'Authentication failed: {msg}')
+                raise errors.ConnectionError(f'Authentication failed: {msg}')
+            # normalized digits-only code
+            self.totp = result.code
             self._logger.info('TOTP received in connection options')
 
         # OAuth authentication setup
@@ -974,13 +1030,11 @@ def send_startup(totp_value=None):
                             short_msg = match.group(1).strip() if match else error_msg.strip()
 
                             if "Invalid TOTP" in short_msg:
-                                print("Authentication failed: Invalid TOTP token.")
-                                self._logger.error("Authentication failed: Invalid TOTP token.")
+                                self._logger.error(f"Authentication failed: {INVALID_TOTP_MSG}")
                                 self.close_socket()
-                                raise errors.ConnectionError("Authentication failed: Invalid TOTP token.")
+                                raise errors.ConnectionError(f"Authentication failed: {INVALID_TOTP_MSG}")
 
                             # Generic error fallback
-                            print(f"Authentication failed: {short_msg}")
                             self._logger.error(short_msg)
                             raise errors.ConnectionError(f"Authentication failed: {short_msg}")
                         else:
@@ -993,23 +1047,20 @@ def send_startup(totp_value=None):
 
                     # ✅ If TOTP not provided initially, prompt only once
                     if not totp:
-                        timeout_seconds = 30  # 5 minutes timeout
+                        timeout_seconds = 300  # 5 minutes timeout
                         try:
                             print("Enter TOTP: ", end="", flush=True)
                             ready, _, _ = select.select([sys.stdin], [], [], timeout_seconds)
                             if ready:
                                 totp_input = sys.stdin.readline().strip()
 
-                                # ❌ Blank TOTP entered
-                                if not totp_input:
-                                    self._logger.error("Invalid TOTP: Cannot be empty.")
-                                    raise errors.ConnectionError("Invalid TOTP: Cannot be empty.")
-
-                                # ❌ Validate TOTP format (must be 6 digits)
-                                if not totp_input.isdigit() or len(totp_input) != 6:
-                                    print("Invalid TOTP format. Please enter a 6-digit code.")
-                                    self._logger.error("Invalid TOTP format entered.")
-                                    raise errors.ConnectionError("Invalid TOTP format: Must be a 6-digit number.")
+                                # Validate using local precedence-based validator
+                                result = validate_totp_code(totp_input, totp_is_valid=None)
+                                if not result.ok:
+                                    msg = INVALID_TOTP_MSG
+                                    self._logger.error(f"Authentication failed: {msg}")
+                                    raise errors.ConnectionError(f"Authentication failed: {msg}")
+                                totp_input = result.code
                                 # ✅ Valid TOTP — retry connection
                                 totp = totp_input
                                 self.close_socket()