diff --git a/lib/ex_fix/session.ex b/lib/ex_fix/session.ex
index 1e923f0..13f4571 100644
--- a/lib/ex_fix/session.ex
+++ b/lib/ex_fix/session.ex
@@ -480,7 +480,7 @@ defmodule ExFix.Session do
             reject_msg =
               build_message(config, @msg_type_reject, out_lastseq, [
                 {@field_session_reject_reason, "10"},
-                {@field_text, "SendingTime acccuracy problem"}
+                {@field_text, "SendingTime accuracy problem"}
               ])
 
             {:ok, [reject_msg],
@@ -720,7 +720,7 @@ defmodule ExFix.Session do
   end
 
   defp validate_sending_time(session_name, %Session{config: config, out_lastseq: out_lastseq} = session, %InMessage{fields: fields, other_msgs: other}, expected_seqnum) do
-    %SessionConfig{time_service: time_service, session_handler: handler, env: env} = config
+    %SessionConfig{time_service: time_service, session_handler: handler, env: env, sending_time_tolerance: tolerance} = config
 
     now =
       case time_service do
@@ -733,7 +733,7 @@ defmodule ExFix.Session do
       {@field_sending_time, st} ->
         with {:ok, sending_dt} <- DateUtil.parse_date(st),
              diff <- abs(DateTime.to_unix(now) - DateTime.to_unix(sending_dt)),
-             true <- diff <= 120 do
+             true <- diff <= tolerance do
           :ok
         else
           _ ->
@@ -743,7 +743,7 @@ defmodule ExFix.Session do
             reject_msg =
               build_message(config, @msg_type_reject, out_lastseq, [
                 {@field_session_reject_reason, "10"},
-                {@field_text, "SendingTime acccuracy problem"}
+                {@field_text, "SendingTime accuracy problem"}
               ])
 
             out_lastseq = out_lastseq + 1
diff --git a/lib/ex_fix/session_config.ex b/lib/ex_fix/session_config.ex
index 585ffa9..51c7696 100644
--- a/lib/ex_fix/session_config.ex
+++ b/lib/ex_fix/session_config.ex
@@ -26,6 +26,7 @@ defmodule ExFix.SessionConfig do
             transport_mod: :gen_tcp,
             transport_options: [],
             time_service: nil,
+            sending_time_tolerance: 120,
             env: %{}
 
   @type t :: %__MODULE__{}
diff --git a/test/session_test.exs b/test/session_test.exs
index 7b5c9ef..1824790 100644
--- a/test/session_test.exs
+++ b/test/session_test.exs
@@ -406,7 +406,7 @@ defmodule ExFix.SessionTest do
     assert reject_msg.target == "SELLSIDE"
     assert reject_msg.orig_sending_time == @t_plus_1
     assert :lists.keyfind("373", 1, reject_msg.body) == {"373", "10"}
-    assert :lists.keyfind("58", 1, reject_msg.body) == {"58", "SendingTime acccuracy problem"}
+    assert :lists.keyfind("58", 1, reject_msg.body) == {"58", "SendingTime accuracy problem"}
   end
 
   test "PossDupFlag=Y and OrigSendingTime not specified (p. 51)", %{config: cfg} do
@@ -617,7 +617,7 @@ defmodule ExFix.SessionTest do
     assert reject_msg.target == "SELLSIDE"
     assert reject_msg.orig_sending_time == @t_plus_1
     assert :lists.keyfind("373", 1, reject_msg.body) == {"373", "10"}
-    assert :lists.keyfind("58", 1, reject_msg.body) == {"58", "SendingTime acccuracy problem"}
+    assert :lists.keyfind("58", 1, reject_msg.body) == {"58", "SendingTime accuracy problem"}
 
     assert logout_msg.seqnum == 7
     assert logout_msg.msg_type == @msg_type_logout
@@ -627,6 +627,36 @@ defmodule ExFix.SessionTest do
     assert :lists.keyfind("58", 1, logout_msg.body) == {"58", "Incorrect SendingTime value"}
   end
 
+  test "SendingTime accuracy with custom tolerance", %{config: cfg} do
+    # Test with custom tolerance of 30 seconds
+    custom_config = %SessionConfig{cfg | sending_time_tolerance: 30}
+    {:ok, session} = Session.init(custom_config)
+    session = %Session{session | status: :online, in_lastseq: 10, out_lastseq: 5}
+
+    seq = 11
+    # Use 1 minute difference (60 seconds), which should exceed 30 second tolerance
+    incoming_data =
+      build_message(
+        @msg_type_execution_report,
+        seq,
+        "SELLSIDE",
+        "BUYSIDE",
+        DateTime.add(@t0, 60, :second),
+        [{@field_account, "1234"}]
+      )
+
+    session = Session.set_time(session, @t0)
+    {:logout, msgs_to_send, session} = Session.handle_incoming_data(session, incoming_data)
+
+    assert Session.get_status(session) == :disconnecting
+    assert length(msgs_to_send) == 2
+    [reject_msg, _logout_msg] = msgs_to_send
+
+    assert reject_msg.msg_type == @msg_type_reject
+    assert :lists.keyfind("373", 1, reject_msg.body) == {"373", "10"}
+    assert :lists.keyfind("58", 1, reject_msg.body) == {"58", "SendingTime accuracy problem"}
+  end
+
   test "Checksum error (p. 55)", %{config: cfg} do
     # > CheckSum error is not the last field of message, value doesn't have length of 3, or isn't delimited by SOH
     # Ignore message - don't increment expected MsgSeqNum