3GPP Scout / Reference / 5GMM causes / Causes #97 and #99 in 5GMM and 5GSM
TS 24.5015GMM cause5GSM cause
Covers
TS 24.501 words these values in parallel, so they share this page. Each has its own section with the spec text and a plain explanation.
In plain words
The equipment sending this cause received a message whose type it does not recognize because the type is undefined or not implemented.
Our summary of the spec text quoted below.
Message type non-existent or not implemented
Source: 3GPP TS 24.501 V20.1.0, clause 9.11.3.2, table 9.11.3.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
This 5GMM cause indicates that the equipment sending this 5GMM cause has received a message with a message type it does not recognize either because this is a message not defined [...]
Source: 3GPP TS 24.501 V20.1.0, clause A.4. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
In plain words
The equipment sending this cause has received a message whose type is undefined or not implemented by that equipment.
Our summary of the spec text quoted below.
Message type non-existent or not implemented
Source: 3GPP TS 24.501 V20.1.0, clause 9.11.4.2, table 9.11.4.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
This 5GSM cause indicates that the equipment sending this 5GSM cause has received a message with a message type it does not recognize either because this is a message not defined [...]
Source: 3GPP TS 24.501 V20.1.0, clause B.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
In plain words
The equipment sending this cause received a message containing information elements it does not recognize because their identifier is undefined or not implemented.
Our summary of the spec text quoted below.
Information element non-existent or not implemented
Source: 3GPP TS 24.501 V20.1.0, clause 9.11.3.2, table 9.11.3.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
This 5GMM cause indicates that the equipment sending this 5GMM cause has received a message which includes information elements not recognized because the information element identifier is not defined or it is [...]
Source: 3GPP TS 24.501 V20.1.0, clause A.4. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
In plain words
The equipment sending this cause has received a message containing an information element whose identifier is undefined or not implemented by that equipment.
Our summary of the spec text quoted below.
Information element non-existent or not implemented
Source: 3GPP TS 24.501 V20.1.0, clause 9.11.4.2, table 9.11.4.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
This 5GSM cause indicates that the equipment sending this 5GSM cause has received a message which includes information elements not recognized because the information element identifier is not defined or it is [...]
Source: 3GPP TS 24.501 V20.1.0, clause B.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
TS 24.301 defines the corresponding causes for EPS. Their pages quote the EPS wording.
3GPP Scout built this page from TS 24.501 V20.1.0 as indexed on 2026-10-15. The quotes are copied from the spec, and code checks each one against the stored text and the 3GPP archive file before publishing. The plain-words lines were written by an AI model (GPT-6 Sol) and checked against the quotes by a second AI model from another company (Claude Opus 5.5). The official 3GPP text governs.