---
title: Reject
seo:
  title: Reject | FIX Session
  description: "FIX session Reject reference: field layout, repeating groups,
    supported values, and message-specific behavior."
sidebar:
  label: Reject
---
`MsgType(35)=Reject(3)`

Direction: **Both directions**.

Reject a message that violates the session protocol or dictionary.

## Field Layout

See [FIX Message Layouts](/reference/fix-message-layouts) for field ordering and presence rules.

| Field | Type | Presence | Behavior |
| --- | --- | --- | --- |
| `RefSeqNum(45)` | [`SEQNUM`](/reference/fix-data-types#seqnum) | Required |  |
| `RefTagID(371)` | [`INT`](/reference/fix-data-types#int) | Optional |  |
| `RefMsgType(372)` | [`STRING`](/reference/fix-data-types#string) | Optional |  |
| `SessionRejectReason(373)` | [`INT`](/reference/fix-data-types#int) | Optional | <span style="overflow-wrap:anywhere">Client reports may use any listed reason. Exchange reports identify the detected session error.</span><br/><br/>Supported values:<br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=INVALID_TAG_NUMBER(0)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=REQUIRED_TAG_MISSING(1)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=TAG_NOT_DEFINED_FOR_THIS_MESSAGE_TYPE(2)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=UNDEFINED_TAG(3)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=TAG_SPECIFIED_WITHOUT_A_VALUE(4)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=VALUE_IS_INCORRECT(5)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=INCORRECT_DATA_FORMAT_FOR_VALUE(6)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=DECRYPTION_PROBLEM(7)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=SIGNATURE_PROBLEM(8)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=COMPID_PROBLEM(9)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=SENDINGTIME_ACCURACY_PROBLEM(10)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=INVALID_MSGTYPE(11)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=XML_VALIDATION_ERROR(12)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=TAG_APPEARS_MORE_THAN_ONCE(13)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=TAG_SPECIFIED_OUT_OF_REQUIRED_ORDER(14)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=REPEATING_GROUP_FIELDS_OUT_OF_ORDER(15)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=INCORRECT_NUMINGROUP_COUNT_FOR_REPEATING_GROUP(16)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=NON_DATA_VALUE_INCLUDES_FIELD_DELIMITER(17)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=INVALID_UNSUPPORTED_APPLICATION_VERSION(18)</code><br/><code style="overflow-wrap:anywhere">SessionRejectReason(373)=OTHER(99)</code> |
| `Text(58)` | [`STRING`](/reference/fix-data-types#string) | Optional |  |