diff --git a/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverBase.cs b/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverBase.cs
index ef934a19..8b2e537e 100644
--- a/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverBase.cs
+++ b/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverBase.cs
@@ -41,6 +41,11 @@ namespace EnvelopeGenerator.Domain.Entities
         [Column("CHANGED_WHEN", TypeName = "datetime")]
         public DateTime? ChangedWhen { get; set; }
 
+        [Column("PHONE_NUMBER")]
+        [StringLength(20)]
+        [RegularExpression(@"^\+[0-9]+$", ErrorMessage = "Phone number must start with '+' followed by digits.")]
+        public string? PhoneNumber { get; set; }
+
         public (int Envelope, int Receiver) Id => (Envelope: EnvelopeId, Receiver: ReceiverId);
     }
 }
\ No newline at end of file