diff --git a/src/HeboTech.ATLib/DTOs/SmsSubmitRequest.cs b/src/HeboTech.ATLib/DTOs/SmsSubmitRequest.cs
index 1dc11d2..ede6e5e 100644
--- a/src/HeboTech.ATLib/DTOs/SmsSubmitRequest.cs
+++ b/src/HeboTech.ATLib/DTOs/SmsSubmitRequest.cs
@@ -34,31 +34,10 @@ public SmsSubmitRequest(
             PhoneNumber phoneNumber,
             string message,
             CharacterSet codingScheme)
-            : this(
-                  phoneNumber,
-                  message,
-                  codingScheme,
-                  ValidityPeriod.NotPresent())
-        {
-        }
-
-        /// <summary>
-        /// Creates a data object for submitting an SMS in PDU format.
-        /// </summary>
-        /// <param name="phoneNumber">The receiver phone number</param>
-        /// <param name="message">The message to send</param>
-        /// <param name="codingScheme">The coding scheme to use</param>
-        /// <param name="validityPeriod">The validity period to use</param>
-        public SmsSubmitRequest(
-            PhoneNumber phoneNumber,
-            string message,
-            CharacterSet codingScheme,
-            ValidityPeriod validityPeriod)
         {
             PhoneNumber = phoneNumber;
             Message = message;
             CodingScheme = codingScheme;
-            ValidityPeriod = validityPeriod;
         }
 
         public PhoneNumber PhoneNumber { get; }