ISO8583 Response Codes For Transaction Processing - NeaPay

ISO8583 Response Codes for Transaction processing

Posted on 29th Jan 2021 130291 views

List of ISO8583 Response Codes, description and use with Video guide of example in the ISO8583 Simulator . Video below

Wikipedia already has a very in-depth description of the ISO 8583 standard.

In the highly competitive and time-sensitive world of payment processing, clarity in communication is paramount. Every electronic financial transaction—from a simple ATM withdrawal to a complex e-commerce purchase—requires a response, and this response is codified by the ISO 8583 Response Code (Data Element 39).

For payment technology providers like NeaPay, which offer ISO 8583 interfaces, simulators, and switching solutions, the handling, mapping, and generation of these response codes is a core function that ensures system interoperability, clear customer feedback, and accurate internal accounting.

What are ISO 8583 Response Codes (DE 39)?

The ISO 8583 Response Code, contained in Data Element 39 (DE 39), is a two-digit or three-digit numeric field that is returned in the response message (e.g., MTI '1110' for an authorization response) to indicate the final status of a transaction requested in the original message.

These codes are standardized to ensure that all parties in the payment chain—the terminal, the acquirer, the network, and the issuer—understand why a transaction was approved, declined, or failed due to a system error.

Key Categories of Response Codes:

Response codes generally fall into three broad categories:

Category	Example Codes	Meaning
Success/Approval	00, 08, 11	The transaction was successfully authorized or completed.
Declined (Soft)	01, 02, 19	The transaction was declined, but the card is valid, and the request can sometimes be retried or referred to the issuer.
Declined (Hard)	04, 41, 54, 57	The transaction was declined, usually due to a fatal reason (e.g., lost card, expired card, insufficient funds) and should not be retried.
System/Network Error	91, 96	The transaction failed due to an issue with a system, link, or component (e.g., Issuer unavailable, System malfunction).

NeaPay's Role in Response Code Processing

NeaPay's suite of products—including the ISO 8583 Simulator, Converter, and Card Switch Router—deals with response codes in several critical ways:

1. Authorization Response Generation (Issuer Simulation)

When the NeaPay Simulator acts as an Issuing Host during testing, it is responsible for generating the correct response codes based on defined scenarios:

• Rule-Based Authorization: Test cases in the Simulator allow defining specific conditions (e.g., if Amount (DE 4) > $100 and Card Type = Savings (DE 3), return code 51 (Not Sufficient Funds)). This allows banks and processors to rigorously test how their acquiring system handles every possible decline reason.

• Response Code Customization: As ISO 8583 is a base standard, many card schemes or national switches (which NeaPay products support) have proprietary or extended codes. NeaPay's configurable platforms allow these non-standard codes to be precisely generated for compliance testing.

2. Response Code Mapping and Conversion

In real-world payment networks, a NeaPay Converter or Switch may act as a bridge between different protocol versions or between ISO 8583 and modern APIs (like JSON/REST). This requires careful response code mapping:

• ISO 8583 to Internal/External API: If an incoming ISO 8583 transaction is converted to a JSON API call for an internal authorization host, the external system will return its own status. The NeaPay Converter must accurately map the API status back to the correct two-digit ISO 8583 response code before sending the message back to the Acquirer.

  • Example: Internal API returns status "Card_Blocked" $rightarrow$ NeaPay maps this to ISO 8583 code 57 (Transaction not permitted to cardholder) or 04 (Pick Up Card), depending on the scheme rules.

• Response Code Normalization: NeaPay's Switch can normalize response codes across multiple connections, ensuring a consistent set of decline reasons is presented to the originating terminal or acquirer, simplifying the management of complex multi-network environments.

3. Error Handling and System Reliability

Response codes in the 90 series are particularly critical as they signify system errors, and NeaPay products are designed to manage the fallout:

• Switch/Host Failure: If an issuer connected to the NeaPay Switch fails to respond (times out), the Switch can be configured to send a standard network error code like 91 (Issuer or Switch Inoperative) back to the originator.

• Stand-in Processing: In advanced configurations, if the primary issuer link is down and returns a 91, the NeaPay Switch can invoke a Stand-In-Authorization (STIP) service. This service can approve small-value, low-risk transactions, returning an 00 (Approved), thus maintaining service continuity even when a critical component is unavailable.

Essential ISO 8583 Response Codes and Their NeaPay Handling

While the full list of codes is extensive, certain codes drive the majority of business logic and are rigorously tested using NeaPay's tools:

Essential ISO 8583 Response Codes

NeaPay Code (DE 39)	Description	NeaPay Product Handling
00	Approved or Completed Successfully	Simulator returns this for passing test cases. Switch ensures all internal approvals map correctly to this code before forwarding.
05	Do Not Honor	A general decline code used when a specific reason is not disclosed. Simulator uses this to test general soft-decline logic on acquiring systems.
14	Invalid Card Number (No Such Number)	Simulator/Authorization Host validates the Primary Account Number (PAN). If invalid, this code is returned immediately, testing the acquirer's ability to handle bad data.
51	Not Sufficient Funds	A common hard decline. Simulator ensures this code triggers the correct terminal message ("Insufficient Funds") without allowing retries.
54	Expired Card	A hard decline that requires the card to be picked up. Simulator tests the terminal's compliance with card pick-up prompts.
55	Incorrect Personal Identification Number (PIN)	Tests PIN validation logic. Simulator is configured to check encrypted PIN Block (DE 52) against a stored value and return 55 on failure.
91	Issuer or Switch Inoperative	Switch/Simulator tests routing failure and Stand-In behavior. NeaPay Switch can generate this code when an upstream connection times out.
96	System Malfunction	A critical system error. Used in performance testing with the NeaPay Simulator to measure system stability under stress.

ISO8583 v1987 - HISO87

The following table shows response codes and their meanings for ISO 8583-1987, later versions uses 3 and 4 digit response codes.

HISO87 Response codes full list [ISO8583 v1987]

Code	Description
00	Approved or completed successfully
01	Refer to card issuer
02	Refer to card issuer's special conditions
03	Invalid merchant
04	Pick-up
05	Do not honor
06	Error
07	Pick-up card, special condition
08	Honour with identification
09	Request in progress
10	Approved for partial amount
11	Approved (VIP)
12	Invalid transaction
13	Invalid amount
14	Invalid card number (no such number)
15	No such issuer
16	Approved, update track 3
17	Customer cancellation
18	Customer dispute
19	Re-enter transaction
20	Invalid response
21	No action taken
22	Suspected malfunction
23	Unacceptable transaction fee
24	File update not supported by receiver
25	Unable to locate record on file
26	Duplicate file update record, old record replaced
27	File update field edit error
28	File update file locked out
29	File update not successful, contact acquirer
30	Format error
31	Bank not supported by switch
32	Completed partially
33	Expired card
34	Suspected fraud
35	Card acceptor contact acquirer
36	Restricted card
37	Card acceptor call acquirer security
38	Allowable PIN tries exceeded
39	No credit account
40	Requested function not supported
41	Lost card
42	No universal account
43	Stolen card, pick-up
44	No investment account
45-50	Reserved for ISO use
51	Not sufficient funds
52	No checking account
53	No savings account
54	Expired card
55	Incorrect personal identification number
56	No card record
57	Transaction not permitted to cardholder
58	Transaction not permitted to terminal
59	Suspected fraud
60	Card acceptor contact acquirer
61	Exceeds withdrawal amount limit
62	Restricted card
63	Security violation
64	Original amount incorrect
65	Exceeds withdrawal frequency limit
66	Card acceptor call acquirer's security department
67	Hard capture (requires that card be picked up at ATM)
68	Response received too late
69-74	Reserved for ISO use
75	Allowable number of PIN tries exceeded
76-89	Reserved for private use
76-89	Reserved for private use
76-89	Reserved for private use
76-89	Reserved for private use
90	Cutoff is in process (switch ending a day's business and starting the next. Transaction can be sent again in a few minutes)
91	Issuer or switch is inoperative
92	Financial institution or intermediate network facility cannot be found for routing
93	Transaction cannot be completed. Violation of law
94	Duplicate transmission
95	Reconcile error
96	System malfunction
97-99	Reserved for national use
Zero A-9Z	Reserved for ISO use
A Zero-MZ	Reserved for national use
N Zero-ZZ	Reserved for private use

ISO8583 v1993 - HISO93

HISO93 Response codes full list [ISO8583 v1993]

Code	Description
000‑099	Used in 1110, 1120, 1121, 1140 and 1210, 1220, 1221 and 1240 messages to indicate that the transaction has been approved.
000	approved
001	honour with identification
002	approved for partial amount
003	approved (VIP)
004	approved, update track 3
005	approved, account type specified by card issuer
006	approved for partial amount, account type specified by card issuer
007	approved, update ICC
008‑059	reserved for ISO use
060‑079	reserved for national use
080‑099	reserved for private use
100‑199	Used in 1110, 1120, 1121, 1140 and 1210, 1220, 1221 and 1240 messages to indicate that the transaction has been processed for authorization by or on behalf of the card issuer and has been denied (not requiring a card pick-up)
100	do not honour
101	expired card
102	suspected fraud
103	card acceptor contact acquirer
104	restricted card
105	card acceptor call acquirer's security department
106	allowable PIN tries exceeded
107	refer to card issuer
108	refer to card issuer's special conditions
109	invalid merchant
110	invalid amount
111	invalid card number
112	PIN data required
113	unacceptable fee
114	no account of type requested
115	requested function not supported
116	not sufficient funds
117	incorrect PIN
118	no card record
119	transaction not permitted to cardholder
120	transaction not permitted to terminal
121	exceeds withdrawal amount limit
122	security violation
123	exceeds withdrawal frequency limit
124	violation of law
125	card not effective
126	invalid PIN block
127	PIN length error
128	PIN key synch error
129	suspected counterfeit card
130‑159	reserved for ISO use
160‑179	reserved for national use
180‑199	reserved for private use
200‑299	Used in 1110, 1120, 1121, 1140 and 1210, 1220, 1221 and 1240 messages to indicate that the transaction has been processed for authorization by or on behalf of the card issuer and has been denied requiring the card to be picked up.
200	do not honour
201	expired card
202	suspected fraud
203	card acceptor contact acquirer
204	restricted card
205	card acceptor call acquirer's security department
206	allowable PIN tries exceeded
207	special conditions
208	lost card
209	stolen card
210	suspected counterfeit card
211‑259	reserved for ISO use
260‑279	reserved for national use
280‑299	reserved for private use
300‑399	Used in 1314, 1324, 1325 and 1344 messages to indicate the result of the file action.
300	successful
301	not supported by receiver
302	unable to locate record on file
303	duplicate record, old record replaced
304	field edit error
305	file locked out
306	not successful
307	format error
308	duplicate, new record rejected
309	unknown file
310‑359	reserved for ISO use
360‑379	reserved for national use
380‑399	reserved for private use
400‑499	Used in 1430, 1432, 1440 and 1442 messages to indicate the result of the reversal or chargeback.
400	accepted
401‑459	reserved for ISO use
460‑479	reserved for national use
480‑499	reserved for private use
500‑599	Used in 1510, 1512, 1530 and 1532 messages to indicate the result of a reconciliation.
500	reconciled, in balance
501	reconciled, out of balance
502	amount not reconciled, totals provided
503	totals not available
504	not reconciled, totals provided
505‑559	reserved for ISO use
560‑579	reserved for national use
580‑599	reserved for private use
600‑699	Used in 1614, 1624, 1625, and 1644 messages
600	accepted
601	not able to trace back original transaction
602	invalid reference number
603	reference number/PAN incompatible
604	POS photograph is not available
605	item supplied
606	request cannot be fulfilled - required/requested documentation is not available
607‑659	reserved for ISO use
660‑679	reserved for national use
680‑699	reserved for private use
700‑799	Used in 1720, 1721, 1740, 1722, 1723 and 1742 messages.
700	accepted
701‑749	reserved for ISO use
750‑769	reserved for national use
770‑799	reserved for private use
800‑899	Used in 1814, 1824, 1825 and 1844 messages.
800	accepted
801‑859	reserved for ISO use
860‑879	reserved for national use
880‑899	reserved for private use
900	Advice acknowledged, no financial liability accepted
901	Advice acknowledged, financial liability accepted
902‑949	Used in request response and advice response messages to indicate transaction could not be processed.
902	invalid transaction
903	re-enter transaction
904	format error
905	acquirer not supported by switch
906	cutover in process
907	card issuer or switch inoperative
908	transaction destination cannot be found for routing
909	system malfunction
910	card issuer signed off
911	card issuer timed out
912	card issuer unavailable
913	duplicate transmission
914	not able to trace back to original transaction
915	reconciliation cutover or checkpoint error
916	MAC incorrect
917	MAC key sync error
918	No communication keys available for use
919	encryption key sync error
920	security software/hardware error - try again
921	security software/hardware error - no action
922	message number out of sequence
923	request in progress
924‑929	reserved for ISO use
930‑939	reserved for national use
940‑949	reserved for private use
950‑999	Used in advice response messages (1x3x) to indicate the reason for rejection of the transfer of financial liability.
950	violation of business arrangement
951‑983	reserved for ISO use
984‑991	reserved for national use
992‑999	reserved for private use

For organizations leveraging NeaPay's ISO 8583 products, response codes are not just error flags; they are the definitive signal of transaction state. By providing configurable simulators, robust switching logic, and precise conversion capabilities, NeaPay ensures that its clients can confidently process, test, and troubleshoot the intricate web of financial transactions, knowing that every approval, decline, or error is communicated with industry-standard accuracy.