Dual vs. Single Message Systems

Single Message System does not apply to you, unless you have configured your BINs to support single message system at the card scheme.

The Dual Message System follows a payment messaging standard which provides separate messages for the authorisation and clearing (presentment) stages. In contrast, the Single Message System combines the authorisation and clearing stages of a payment transaction into a single message. See:

You should check with your Thredd account manager and Mastercard or Visa representative to see which method is available for your region or country.

Dual Message System

This system provides separate messages for authorisation and clearing. It is a prominent method in Europe and also used in other regions.

Figure: Dual Message System

The initial Message Type Idenfier (MTID) is an 0100 Authorisation message in which the billed amount or settlement amount has not yet been finalised (i.e., bill amount and settlement amount status is open). This is followed at a later stage by the 1240 (Mastercard) or 05/06/07 (Visa) Clearing message, in which the billing amount (Bill_Amt) and settlement amount (Settle_Amt) are finalised. Thredd receives a daily clearing file from the card scheme and generates the clearing messages which are sent to the Program Manager via EHI.

How to handle Dual Messages

  • When your systems receive the 0100 Authorisation message, you should respond with an approve or deny. If approved, then block the approved amount plus any transaction fees on the card.

  • When your systems receive the 1240 or 05/06/07 Clearing message (Thredd refer to this as the Presentment), your systems should match the clearing message to the original authorisation message.

Single Message System

Single Message System does not apply to you, unless you have configured your BINs at the card scheme to support single message system.

Single Message System is a transaction processing message standard which combines authorisation and presentment a single message. It is more common in regions such as the US and Asia Pacific and within those regions, for certain types of transactions, such as those where payment is captured at the same time as authorisation.

Thredd connects to Mastercard Debit Switch (MDS) and Visa DPS, which are Card Scheme systems that process messages according to the Single Message System standard. If Thredd receives messages from Single Message Systems, these will be processed and sent via EHI to the external host. Examples of messages unique to Single Message Systems, which Thredd can provide via EHI, include: 0200 Online Financial Requests, 0220 Online Financial Advices and 0420 V Online Financial Reversals.

If you want to receive the relevant online financial messages, you must have configured your BINs at the card scheme to support single message system.

If you want to support Single Message System in regions such as the US and Philippines, but don’t want to update your systems, Thredd offers a Backwards Compatibility Mode which converts messages into their equivalent formats on Dual Message Systems.

Figure 1: Single Message System

The initial Message Type Idenfier (MTID) is an 0200/M online financial request or 0220/Q online financial advice message, in which the billed amount (Bill_Amt) and settlement (Settle_Amt) are finalised.

How to handle Single Messages

  • When your systems receive the 0200/M online financial request, you should respond with approve or deny and deduct the approved amount plus any transaction fees from the card. You may also receive an Online Financial Reversal (0420/V), in which case you must apply the balance change.

For Mastercard Single Message System, the 0200 message may be followed by a 0220 message (e.g., preauthorisations and Automated Fuel Dispensors (AFDs)), in which case you will need to adjust the amount after the final 0220 message.

  • Thredd returns an 0210 message response to the card scheme.

If your issuer operates a Single Message system, you should ideally support the new message types above.

Backwards Compatibility Mode

For existing Thredd customers currently using the Dual Message System who do not want to change their systems to support the Single Message format, Thredd provides a backwards compatibility mode. In this mode, Thredd sends the new message types in a similar way to Dual Messages, as follows:

Authorisation Requests

  • Thredd converts an 0200/M message into an 0100/A message

  • If the message is approved, Thredd creates a 1240/P (Mastercard) or 05, 06, 07 (Visa) message. In this message, the Txn_id field will have the value of "9999" + Txn_id of the original message

Authorisation Advices

  • Thredd converts an 0220/Q message into an 1240/P (Mastercard) or 05/06/07 (Visa) message.

Authorisation Reversals

  • Thredd converts an 0420/V message into an 1240/E (Mastercard) or 25/26/27 (Visa) message.

The contents of the messages will be identical (same EHI fields), except for the message type identifier (MTID) and the transaction_type.