diff --git a/EnvelopeGenerator.Application/Extensions/DTOExtensions.cs b/EnvelopeGenerator.Application/Extensions/DTOExtensions.cs
new file mode 100644
index 00000000..753a08cc
--- /dev/null
+++ b/EnvelopeGenerator.Application/Extensions/DTOExtensions.cs
@@ -0,0 +1,14 @@
+using EnvelopeGenerator.Application.DTOs.Receiver;
+
+namespace EnvelopeGenerator.Application.Extensions
+{
+    public static class DTOExtensions
+    {
+        public static bool IsTotpSecretExpired(this ReceiverReadDto dto, int minutesBeforeExpiration = 30)
+            => dto.TotpExpiration < DateTime.Now.AddMinutes(minutesBeforeExpiration * -1);
+
+        public static bool IsTotpSecretInvalid(this ReceiverReadDto dto) => dto.IsTotpSecretExpired() || dto.TotpSecretkey is null;
+
+        public static bool IsTotpSecretValid(this ReceiverReadDto dto) => !dto.IsTotpSecretInvalid();
+    }
+}
\ No newline at end of file
diff --git a/EnvelopeGenerator.Application/Extensions/MappingExtensions.cs b/EnvelopeGenerator.Application/Extensions/MappingExtensions.cs
index d2ebb946..0d7f19c8 100644
--- a/EnvelopeGenerator.Application/Extensions/MappingExtensions.cs
+++ b/EnvelopeGenerator.Application/Extensions/MappingExtensions.cs
@@ -1,5 +1,4 @@
-using EnvelopeGenerator.Application.DTOs.EnvelopeReceiver;
-using EnvelopeGenerator.Domain.HttpResponse;
+using EnvelopeGenerator.Domain.HttpResponse;
 
 namespace EnvelopeGenerator.Application.Extensions
 {