External Host Interface Integration Guide
13. Chargeback and Chargeback Reversal Messages
Chargeback messages are sent when a dispute-related financial event occurs after a transaction has already been presented. A chargeback can only be created for a transaction that has a linked presentment. In the EHI transaction flow, a chargeback notification is sent to your system, and your system returns an acknowledgement.
As with all EHI messages, Payblr forwards the EHI JSON payload to your configured endpoint. Your system should process the message using the EHI fields, optionally match it to the related financial notification or chargeback, and update dispute, ledger, and reconciliation records according to your internal rules.
Chargeback messages are different from authorization, authorization reversal, and financial reversal messages. They are dispute-related financial notifications and should not be treated as new authorization requests.
Note: For the Payblr integration, document chargeback processing using 1240 / H for chargeback notification and 1240 / K for chargeback reversal.
On this page
13.1 Applicable identifiers
Chargeback and chargeback reversal messages are identified using the EHI fields included in the forwarded JSON payload.
| Field | Expected value | Description |
|---|---|---|
MTID | 1240 | Identifies the message as a financial notification type. |
Txn_Type | H | Identifies a chargeback notification, non-credit. |
Txn_Type | K | Identifies a chargeback reversal. |
Token | Varies | Identifies the card token associated with the transaction. |
TXn_ID / Txn_ID | Varies | Identifies the EHI transaction message. |
Acquirer_Reference_Data_031 | Varies, when present | May be used to match the chargeback to the financial notification. |
Auth_Code_DE38 | Varies, when present | May help match the chargeback to the financial notification. |
Trans_Link | Varies, when present | May help match the chargeback to the financial notification or related chargeback. |
Reason_ID | Varies, when present | Indicates the chargeback reason. |
Dispute_Condition | Varies, when present | Provides additional dispute reason information for chargeback message. |
Network_Chargeback_Reference_Id | Varies, when present | Network chargeback reference identifier. |
1240 / H identifies a chargeback notification, non-credit, and 1240 / K identifies a chargeback reversal.
13.2 Chargeback flow
Chargeback flow
Platform
Payblr
System
Your Systems
13.3 Chargeback reversal flow
Chargeback reversal flow
Platform
Payblr
System
Your Systems
13.4 How your system should process chargeback messages
When your system receives a chargeback message, they should:
- Validate Payblr’s integration headers, signature, timestamp, and original EHI JSON payload before processing.
- Identify the message as a chargeback using
MTID= 1240 andTxn_Type= H. - Check whether the chargeback message was already received or processed using the applicable EHI identifiers.
- Optionally match the chargeback to the related financial notification using the EHI matching criteria.
- Review dispute-related fields such as
Reason_ID,Dispute_Condition, andNetwork_Chargeback_Reference_Id, when present. - Update dispute, ledger, transaction history, and reconciliation records according to your internal rules.
- If no matching financial notification is found, store the chargeback as unmatched and process it according to your reconciliation or exception-handling process.
- Return the required acknowledgement response.
- Store the chargeback message, matching result, response returned, and
x-correlation-idfor audit, duplicate handling, and reconciliation.
13.5 How your system should process chargeback reversal messages
When your system receives a chargeback reversal message, they should:
- Validate Payblr’s integration headers, signature, timestamp, and EHI JSON payload before processing.
- Identify the message as a chargeback reversal using
MTID= 1240 andTxn_Type= K. - Check whether the chargeback reversal was already received or processed.
- Optionally match the chargeback reversal to the original
1240 / Hchargeback message. - Reverse or adjust the previous chargeback-related ledger or dispute impact according to your internal rules.
- If no matching chargeback is found, store the chargeback reversal as unmatched and process it according to your reconciliation or exception-handling process.
- Return the required acknowledgement response.
- Store the chargeback reversal message, matching result, response returned, and
x-correlation-idfor audit, duplicate handling, and reconciliation.
A 1240 / K chargeback reversal reverses the effect of a chargeback, for example reversing the impact on the account balance if the original chargeback changed it.
13.6 Chargeback matching criteria
Your system may match chargeback notifications to the related financial notification using the original EHI fields.
| Incoming message | Match to | Matching criteria |
|---|---|---|
1240 / H chargeback notification, non-credit | Related financial notification: 1240 / P or 1200 / W | Use the applicable chargeback matching fields when available. |
When matching chargeback notifications, your system may use the following fields when available:
| Matching field | Matching criteria |
|---|---|
Acquirer_Reference_Data_031 | OTHER.Acquirer_Reference_Data_031 = THIS.Acquirer_Reference_Data_031 |
Token | OTHER.Token = THIS.Token |
Auth_Code_DE38 | OTHER.Auth_Code_DE38 = THIS.Auth_Code_DE38, when present |
Trans_Link | OTHER.Trans_Link = THIS.Trans_Link |
Some fields may be blank or unavailable in certain chargeback messages. Your system should store unmatched chargebacks for reconciliation or exception handling when a reliable match cannot be confirmed.
13.7 Chargeback reversal matching criteria
Your system may match a chargeback reversal to the original chargeback message using the original EHI fields.
| Incoming message | Match to | Matching criteria |
|---|---|---|
1240 / K chargeback reversal | Original 1240 / H chargeback notification | Use the same available matching fields as chargeback matching, except the original matched message has Txn_Type = H. |
The matching logic can be understood as:
OTHER.MTID = '1240'
AND OTHER.Txn_Type = 'H'
AND OTHER.Acquirer_Reference_Data_031 = THIS.Acquirer_Reference_Data_031
AND OTHER.Token = THIS.Token
AND OTHER.Auth_Code_DE38 = THIS.Auth_Code_DE38
AND OTHER.Trans_link = THIS.Trans_link1240 / K follows the same matching approach as chargeback matching, except the original transaction to match has Txn_Type = H.
13.8 Processing outcome
| Scenario | Required handling |
|---|---|
| Chargeback received and related financial notification found | Match the chargeback to the financial notification and update dispute, ledger, and reconciliation records. |
| Chargeback received and no financial match found | Store as unmatched and process through reconciliation or exception handling. |
| Chargeback non-credit received | Process according to your dispute and reconciliation rules. |
| Chargeback reversal received and original chargeback found | Reverse or adjust the original chargeback impact. |
| Chargeback reversal received and original chargeback not found | Store as unmatched and process through reconciliation or exception handling. |
| Duplicate chargeback | Do not apply dispute, ledger, balance, or reconciliation impact again. Return the same logical acknowledgement. |
| Duplicate chargeback reversal | Do not reverse or adjust the chargeback impact again. Return the same logical acknowledgement. |
13.9 Required response
Chargeback and chargeback reversal messages should be acknowledged after your system receives and processes the message.
Acknowledgement: Indicates that your system received and processed the chargeback or chargeback reversal message.Responsestatus: Optional. May be included when required by the EHI response contract or program configuration.
For chargeback and chargeback reversal messages, your system generally returns an acknowledgement response instead of a new approve or decline decision.
13.10 Chargeback request examples
| Official guide example | Identifier | Use |
|---|---|---|
| Chargeback | MTID = 1240, Txn_Type = C | Use for chargeback notification reference scenario. |
| Non-Credit Chargeback | MTID = 1240, Txn_Type = H | Use for non-credit chargeback notification reference scenario. |
Chargeback request example with Txn_Type = C, for Mastercard:
{
"AuthenticationAmountUpper": 0.0000,
"FxProviderCardholderRate": 0.0,
"Network_Chargeback_Reference_Id": "2400000015906",
"Acquirer_Reference_Data_031": "74600000000000000000000",
"Currency_Code_Fee": "392",
"Currency_Code_Fee_Settlement": "392",
"Interchange_Amount_Fee": -11.1111,
"Interchange_Amount_Fee_Settlement": -11.1111,
"DCC_Indicator": 0,
"multi_part_txn": 0,
"multi_part_txn_final": 0,
"multi_part_number": 0,
"multi_part_count": 0,
"SettlementIndicator": "0",
"auth_type": "0",
"Matching_Txn_ID": 0,
"Reason_ID": 4001,
"Merch_Name": "WHATST BANK",
"Merch_Street": "CHARGEBACK UK HSBC 5",
"Merch_City": "LONDON",
"Merch_Region": "GBR",
"Merch_Country": "GBR",
"Merch_Postcode": "00000",
"Merch_Tel": "0",
"Merch_URL": "0",
"Merch_Tax_id": "0",
"GPS_POS_Capability": "000000000000000000000000000000000000000000000000",
"GPS_POS_Data": "9613000000000",
"Acquirer_id_DE32": "0000000000",
"ActBal": 0.00,
"Auth_Code_DE38": "000000",
"Avl_Bal": 0.00,
"Bill_Amt": 0.00,
"Bill_Ccy": "826",
"BlkAmt": 0.00,
"Fee_Fixed": 0.00,
"Fee_Rate": 0.00,
"MCC_Code": "6011",
"Merch_ID_DE42": "000000000000000",
"Merch_Name_DE43": "WHATST BANK",
"Proc_Code": "000000",
"Ret_Ref_No_DE37": "000000000000",
"Settle_Amt": 0.00,
"Settle_Ccy": "826",
"Status_Code": "00",
"Token": 100000000,
"Trans_link": "000000000000000000",
"Txn_Amt": 0.0000,
"Txn_CCy": "826",
"Txn_Ctry": "GBR",
"Txn_Desc": "Chargeback",
"Txn_GPS_Date": "2026-01-01 00:00:00.000",
"TXn_ID": 0,
"Txn_Stat_Code": "A",
"Txn_Type": "C",
"MTID": "1240",
"ProductID": 0,
"SubBIN": 0,
"SendingAttemptCount": 0
}13.11 Chargeback reversal request examples
| Official guide example | Identifier | Use |
|---|---|---|
| Chargeback Reversal | MTID = 1240, Txn_Type = K | Use for chargeback reversal reference scenario. |
Chargeback reversal request example with Txn_Type = K, for Mastercard:
{
"AuthenticationAmountUpper": 0.0000,
"FxProviderCardholderRate": 0.0,
"Network_Chargeback_Reference_Id": "2400000015906",
"Acquirer_Reference_Data_031": "74600000000000000000000",
"DCC_Indicator": 0,
"multi_part_txn": 0,
"multi_part_txn_final": 0,
"auth_type": "0",
"Matching_Txn_ID": 0,
"Reason_ID": 4001,
"Merch_Name": "WHATST BANK",
"Merch_Street": "CHARGEBACK UK HSBC 5",
"Merch_City": "LONDON",
"Merch_Region": "GBR",
"Merch_Country": "GBR",
"GPS_POS_Capability": "000000000000000000000000000000000000000000000000",
"GPS_POS_Data": "9613000000000",
"Acquirer_id_DE32": "0000000000",
"ActBal": 0.00,
"Auth_Code_DE38": "000000",
"Avl_Bal": 0.00,
"Bill_Amt": 0.00,
"Bill_Ccy": "826",
"BlkAmt": 0.00,
"MCC_Code": "6011",
"Merch_ID_DE42": "000000000000000",
"Merch_Name_DE43": "WHATST BANK",
"Proc_Code": "000000",
"Ret_Ref_No_DE37": "000000000000",
"Settle_Amt": 0.00,
"Settle_Ccy": "826",
"Status_Code": "00",
"Token": 100000000,
"Trans_link": "000000000000000000",
"Txn_Amt": 0.0000,
"Txn_CCy": "826",
"Txn_Ctry": "GBR",
"Txn_Desc": "Chargeback reversal",
"Txn_GPS_Date": "2026-01-01 00:00:00.000",
"TXn_ID": 0,
"Txn_Stat_Code": "A",
"Txn_Type": "K",
"MTID": "1240",
"ProductID": 0,
"SubBIN": 0,
"SendingAttemptCount": 0
}13.12 Response example
Minimal acknowledgement response:
{
"Acknowledgement": "1"
}13.13 Implementation notes
- Chargeback messages should not be treated as authorization requests.
- Chargeback messages should be processed as dispute-related financial notifications.
1240 / Hidentifies a chargeback notification, non-credit.1240 / Kidentifies a chargeback reversal.- Your system may match chargebacks to the related financial notification when possible.
- Your system may match chargeback reversals to the original
1240 / Hchargeback when possible. - Your system should use
Reason_ID,Dispute_Condition, andNetwork_Chargeback_Reference_Idwhen available for dispute and reconciliation handling. - If no reliable match is found, your system should store the message and route it to reconciliation or exception handling.
- Your system should avoid duplicate dispute, ledger, balance, or reconciliation impact if the same chargeback or chargeback reversal is received more than once.
- Your system should store key identifiers such as
Token,TXn_ID,Acquirer_Reference_Data_031,Auth_Code_DE38,Trans_link,Reason_ID,Network_Chargeback_Reference_Id, andx-correlation-id.