1Processing of ISR payments with PostFinance

If you have your bank account with PostFinance this is the correct documentation that will show you how to setup your processor in order to automatically receive CAMT.054 files.

If you have your account with another bank, you can use our generic ISR processor.

Generally the process of the ISR payment methods is as follow:

  • The buyer receives an invoice document with a slip which contains a number with which the buyer can pay the invoice either through the online banking or by going to a post office.

  • The payment will be credited to the merchant’s bank account including the reference number generated in the first step.

  • The merchant needs to match the payments with the outstanding invoice amount based up on the reference number. This process is called reconciliation.

This processor takes care of all the above steps.

2Sign up

To process ISR payments you only need a PostFinance bank account. The setup of ISR is free of charge. Also the fetching of the reconciliation files is free of charge.

When you switch the processor configuration in our application into the live mode we will guide you through the steps required to request a ISR participant number and the setup of the automated fetching of the reconciliation files. In essence you need a PostFinance bank account and a ISR participant number. Additionally you need to link your bank account with our application to allow the automated fetching of the reconciliation files.


To be able to use this processor you need first to enable the ISR feature in your space. After this step you can configure the ISR processor. You can do so in the feature menu.

We recommend to configure the processor first in the test mode to check and verify if the generated documents fit your needs. For this step you do not need a PostFinance bank account. We will fill in some dummy values.

Once you switch to the live mode you will be guided through the required steps. Keep in mind that those steps might take several days to complete since PostFinance must activate some features which they do only manually.

3.1ISR Printing Settings

In case you are printing the payment slips and send them to your customer you should make sure that the OCR information on the slip (right corner at the bottom) is within the acceptance range otherwise it could happen that you will be charged additional costs if your clients use the slips to pay at the counter. As the printing is very specific to your operating system and your printer this might have to be adjusted. For this you can set the X and Y-Offset to position the ISR slips horizontally and vertically.

The adjustment might be needed because your printer does not print the data onto the paper exactly where it was instructed. This is a common problem.

Further when you plan to print the invoice with the slip you should use the pre-printed slips provided by PostFinance. Ask your account manager for ordering such slips. Typically you will add those paper into a dedicated tray. When setup the automated printing with our application (for example via the Google Cloud Print Service) you can setup a dedicated printer for printing the slip on to the paper from this dedicated tray.

3.2Bank Transfer vs. Invoice

Once the processor is created, you can go ahead and configure the connector(s). There are two different connectors you can choose from:

  • ISR Bank Transfer: The ISR Bank Transfer is used for pre-payment scenarios where you create an invoice document but your client has to pay first the invoice using the ISR slip. Once the money has arrived and could be reconciled you start with the fulfilling the order. The state of the transaction switches after the payment into the Fulfill state.

  • ISR Invoice: The ISR Invoice is used when the customer receives with the goods an invoice to pay. This means you start fulfilling the order before you have received the money. The state of the transaction switches before receiving the payment into the Fulfill state.

3.3Connector Settings

Once the processor is created, you can go ahead and configure the connector(s). In the connector you are able to configure additional settings. You find more information and documentation in the configuration directly. This is why only the very important settings are further explained in detail here:

  • Enable Dunning: You have the option to enable the dunning feature of the application. In this case the system will create a dunning case once your client did not pay the invoice during the payment term. In order to use the dunning system you will have to setup the dunning flows and levels. More information can be found in the Dunning Documentation.

  • Instant Invoice Payment You have the possibility to print a QR code on the invoice document and allow your customers to pay the invoice instantly using another payment method.

  • Payment Term: The payment term defines when the invoice has to be paid before it switches into the dunning or failed state.

  • Allowed Difference: This setting defines the maximal difference between the paid amount by the customer and the captured amount on the invoice. As long as the amount is within this limit then the system marks the invoice still as fully paid even though there might be a little difference to the captured amount.

Once the settings on the connector are stored you are able to offer the ISR payments to your clients.

4Frequently asked Questions

4.1What reconciliation formats do you support?

PostFinance provides a reconciliation file that allows the automatic reconciliation of open invoices. We are able to process the following file formats:

  • ISO 20022 (camt.053.001.04) including Detail Records

  • ISO 20022 (camt.054.001.04) including Detail Records.

We recommend to use CAMT054 because PostFinance offers multiple daily settlements in this format.

4.2How to resolve manually records?

Most of the payments can be processed automatically. However, there are cases where the customer paid too much (exceeding amount) or where the customer used the wrong ISR number to pay the invoice. Those cases are recognized by the system and those manual tasks have to be handled by you. More information can be found in our ISR Records Manual Resolving FAQ entry.

4.3Can I upload the camt files manually?

ISR Statements can also be uploaded manually under Statements. Once the upload is finished the statements will be scheduled for processing. This can take some time. After the files are processed you find a list of processed records under Transaction Records.

As soon as the invoice could be matched the transaction will be marked as paid and the system automatically creates a payment receipt.

4.4Can I download the processed statements?

In case you do want to download the original statements again you can do that by opening the Statement List. The download button will give you access to the original file.

This file can now be used to upload in any other systems in case you are migrating form another system and you do still need to upload payments during the migration period.

4.5What is the structure of the ISR number?

The ISR number used as a reference to reconcile the payment is automatically generated by us: It is structured with a prefix of 7 digits that identifies the merchant’s space and the remaining 20 digits correspond to the merchant reference.

4.6Why do I need to verify my bank account by making a small payment?

We aggregate the reconciliation files of all merchants in one account. As such we receive all files in one FDS account from PostFinance. As such we have to verify if you are allowed to see a particular file by verifying if you are the account holder of that account. We do this verification by requesting a small payment to our bank account. This allows us to ensure that you are really who you claim to be. This protects your data from a malicious user.

4.7How long does it typically take to activate the ISR feature in my PostFinance account?

Once you have started the process by sending the form to PostFinance for applying for the ISR participant number it takes typically 2 to 3 business days.

4.8I have already a participant number. Should I still request a new one?

Yes. When you have already a participant number you most likely also use this in another system. To avoid any conflict we recommend requesting a new participant number.

4.9Do I need the delivery of the reconciliation files to the FDS?

The FDS is the system used by PostFinance to exchange the reconciliation files. To allow an automated process we highly recommend to do this. Otherwise you need to manually upload the camt files into our system.