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PostFinance Pay

About PostFinance Pay

General information about PostFinance Pay

PostFinance has updated its online payment methods for the PostFinance Card, combining "PostFinance Card" and "PostFinance E-Finance" into a single system. Previously, these methods allowed you to choose your preferred payment process and confirm online payment authentication via the PostFinance app, a card reader, or Mobile ID.

With the introduction of PostFinance Pay, these two methods are being merged and enhanced. This new system eliminates the need for a card number and card reader during the payment process. With PostFinance Pay, you can now conveniently confirm online transactions and payment method registrations directly through the PostFinance app.

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Info

PostFinance is an online banking payment method in Switzerland and is the market leader in Swiss payment transactions with a market share of around 60%. With PostFinance merchants can reach over 3.5 million potential customers.

Type

Payments by Online Bank Transfer

Further information can be found on the webpage of PostFinance (https://www.postfinance.ch/de/privat/zahlen-sparen/mobiles-bezahlen/pay.html#/). 

Process Flow Chart

Paygate interface

Definitions

Data formats

Format

Description

a

alphabetical

as

alphabetical with special characters

n

numeric

an

alphanumeric

ans

alphanumeric with special characters

ns

numeric with special characters

bool

boolean expression (true or false)

3

fixed length with 3 digits/characters

..3

variable length with maximum 3 digits/characters

enum

enumeration of allowed values

dttm

ISODateTime (YYYY-MM-DDThh:mm:ss)

Abbreviations

Abbreviation

Description

Comment

CND

condition

M

mandatory

If a parameter is mandatory, then it must be present

O

optional

If a parameter is optional, then it can be present, but it is not required

C

conditional

If a parameter is conditional, then there is a conditional rule which specifies whether it is mandatory or optional

Notice: Please note that the names of parameters can be returned in upper or lower case.

Create PostFinance Pay Authorisation

To create an authorisation with PostFinance Pay, please use the following URL:

https://www.computop-paygate.com/PostFinPay.aspx

Notice: For security reasons, Computop Paygate rejects all payment requests with formatting errors. Therefore, please use the correct data type for each parameter.

The following table describes the encrypted payment request parameters:

Please note that when PostFinance redirects a customer to the callback page, the initiated transaction has not yet been finalized. Therefore, kindly inform the customer on the callback page that the payment is still being processed and that they should not close the page.

If the transaction is to be partially captured later, you need to define this when you initiate the Authorization request by using the captureInfo parameter as described below.

Notice: Please keep in mind that a session expires within 10 minutes. An iFrame integration is not recommended.

KeyFormatCNDDescription

MerchantID

ans..30

M

MerchantID, assigned by Computop. Additionally this parameter has to be passed in plain language too.

TransID

ans..64

M

TransactionID provided by you which should be unique for each payment

RefNr

ans..18

M

Merchant’s unique reference number. Only characters a-zA-Z0-9,-_ are allowed.

Amount

n..10

M

Amount in the smallest currency unit (e.g. EUR Cent). Please contact the Computop Helpdesk, if you want to capture amounts <100 (smallest currency unit).

Currency

a3

M

Currency, three digits DIN / ISO 4217. Only CHF and EUR permissible. Please find an overview here: A1 Currency table

MAC

an64

M

Hash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here:

UserData

ans..1024

O

If specified at request, Paygate forwards the parameter with the payment result to the shop.

ReqId

ans..32

O

To avoid double payments or actions (e.g. by ETM), enter an alphanumeric value which identifies your transaction and may be assigned only once. If the transaction or action is submitted again with the same ReqID, Computop Paygate will not carry out the payment or new action, but will just return the status of the original transaction or action.

Please note that the Computop Paygate must have a finalized transaction status for the first initial action (authentication/authorisation). This does not apply to 3-D Secure authentications that are terminated by a timeout. The 3-D Secure Timeout status does not count as a completed status in which the ReqID functionality on Paygate does not take effect. Submissions with identical ReqID for an open status will be processed regularly.

Notice: Please note that a ReqID is only valid for 12 month, then it gets deleted at the Paygate.

captureinfo

ans..1024

O

New parameter for multiple partial captures. This parameter must be created in JSON format.

The individual parameters in JSON format are following:

  • {"auto":"yes"} → Capturing immediately after authorisation.

    1
    ewogICJhdXRvIjogICJ5ZXMiCn0=
  • {"manual": {"final":"yes"} → Capturing made by the merchant for the Full Amount

    1
    ewogICJtYW51YWwiOiB7CiAgICAiZmluYWwiOiAieWVzIgogIH0KfQ==
  • {"manual": {"final":"no"} → Capturing made by the merchant for the Partial Amount(s).

    1
    ew0KICAibWFudWFsIjogew0KICAgICJmaW5hbCI6ICJubyINCiAgfQ0KfQ==

URLSuccess

ans..256

M

Complete URL which calls up Paygate if payment has been successful. The URL may be called up only via port 443. This URL may not contain parameters: In order to exchange values between Paygate and shop, please use the parameter UserData.

Common notes:

  • We recommend to use parameter "response=encrypt" to get an encrypted response by Paygate

  • However, fraudster may just copy the encrypted DATA-element which are sent to URLFailure and send the DATA to URLSuccess/URLNotify. Therefore ensure to check the "code"-value which indicates success/failure of the action. Only a result of "code=00000000" should be considered successful.

URLFailure

ans..256

M

Complete URL which calls up Paygate if payment has been unsuccessful. The URL may be called up only via port 443. This URL may not contain parameters: In order to exchange values between Paygate and shop, please use the parameter UserData.

Common notes:

  • We recommend to use parameter "response=encrypt" to get an encrypted response by Paygate

  • However, fraudster may just copy the encrypted DATA-element which are sent to URLFailure and send the DATA to URLSuccess/URLNotify. Therefore ensure to check the "code"-value which indicates success/failure of the action. Only a result of "code=00000000" should be considered successful.

Response

a7

O

Status response sent by Paygate to URLSuccess and URLFailure, should be encrypted. For this purpose, transmit Response=encrypt parameter.

URLNotify

ans..256

M

Complete URL which Paygate calls up in order to notify the shop about the payment result. The URL may be called up only via port 443. It may not contain parameters: Use the UserDataparameter instead.

Common notes:

  • Before follow-up actions (capture / credit / reversal) are carried out on an existing transaction, the first Notify must have been answered by the shop.

  • Fraudster may just copy the encrypted DATA-element which are sent to URLFailure and send the DATA to URLSuccess/URLNotify. Therefore ensure to check the "code"-value which indicates success/failure of the action. Only a result of "code=00000000" should be considered successful.

Plain

ans..50

O

A single value to be set by the merchant to return some information unencrypted in response/notify, e.g. the MID.

"Plain"-parameter is part of encrypted "Data" in Computop Paygate and therefore protected against manipulation.

Custom

ans..1024

O

"Custom"-parameter is added to the request data before encryption and is part of encrypted "Data" in Computop Paygate request. By this they are protected against manipulation by a consumer.

The Custom-value is added to the Computop Paygate response in plain text and the "|" is replaced by a "&". By this you can put a single value into Custom-parameter and get multiple key-value-pairs back in response for your own purpose.

Please find a sample here: Custom

Parameters for payments with PostFinance Pay

The following table gives the result parameters which Computop Paygate transmits to URLSuccess or URLFailure and URLNotify. If you have specified the Response=encrypt parameter, the following parameters are sent Blowfish encrypted to your system:

pls. be prepared to receive additional parameters at any time and do not check the order of parameters

the key (e.g. MerchantId, RefNr) should not be checked case-sentive

KeyFormatCNDDescription

mid

ans..30

M

MerchantID, assigned by Computop

PayID

an32

M

ID assigned by Paygate for the payment, e.g. for referencing in batch files as well as for capture or credit request.

XID

an32

M

ID for all single transactions (authorisation, capture, credit note) for one payment assigned by Paygate

TransID

ans..64

M

TransactionID provided by you which should be unique for each payment

Status

a..50

M

OK (URLSuccess) or FAILED (URLFailure)

Description

ans..1024

M

Further details in the event that payment is rejected. Please do not use the Description but the Code parameter for the transaction status analysis!

Code

an8

M

Error code according to Paygate Response Codes (A4 Error codes)

RefNr

ans..18

M

Merchant’s unique reference number. Only characters a-zA-Z0-9,-_ are allowed.

MAC

an64

M

Hash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here:

UserData

ans..1024

O

If specified at request, Paygate forwards the parameter with the payment result to the shop.

Plain

ans..50

O

A single value to be set by the merchant to return some information unencrypted in response/notify, e.g. the MID.

"Plain"-parameter is part of encrypted "Data" in Computop Paygate and therefore protected against manipulation.

Custom

ans..1024

O

"Custom"-parameter is added to the request data before encryption and is part of encrypted "Data" in Computop Paygate request. By this they are protected against manipulation by a consumer.

The Custom-value is added to the Computop Paygate response in plain text and the "|" is replaced by a "&". By this you can put a single value into Custom-parameter and get multiple key-value-pairs back in response for your own purpose.

Please find a sample here: Custom

Return parameters for URLSuccess, URLFailure and URLNotify with PostFinance Pay

Authentication and approval process on PostFinance

  1. Initial redirection to authentication:

    • Upon initiating a transaction, customers will be redirected to the redirect page of PostFinance to complete authentication.

    • The system will display the Paygate status AUTHORIZE_REQUEST during this period.

  2. Timeout handling:

    • Customers are given a maximum of 8 minutes to complete the authentication steps on the redirection page.

    • If the customer fails to complete authentication within 8 minutes, they will be redirected to the URLFailure page with the Paygate status of FAILED.

    • PostFinance defines this 8-minute timeout period.

  3. Post-Authentication handling:

    • Once the customer completes the authentication on the redirection page, they will be redirected to the callback page.

    • On the callback page the customer must provide payment approval to proceed with the transaction.

  4. Payment approval monitoring:

    • After authentication, if the customer does not immediately approve the payment:

      • Paygate will poll the transaction status every 5 seconds.

      • If the transaction status is returned as successful Paygate will initiate an authorization request for the customer.

        • Based on the result of the authorization request:

          • If successful, the customer will be redirected to the URLSuccess page and the Paygate status will update to AUTHORIZED.

          • If unsuccessful, the customer will be redirected to the URLFailure page and the Paygate status will update to FAILED.

      • If the transaction times out or an error occurs during the payment approval, the customer will be redirected to the URLFailure page and the Paygate status will update to FAILED.

Capture

Regarding the timelines of captures and refunds, please note also the information on PostFinance FAQ page.

Captures are possible via a Server-to-Server connection. To carry out a capture via a Server-to-Server connection, please use the following URL:

https://www.computop-paygate.com/capture.aspx

Notice: For security reasons, Computop Paygate rejects all payment requests with formatting errors. Therefore, please use the correct data type for each parameter.

The following table describes the encrypted payment request parameters:

KeyFormatCNDDescription

MerchantID

ans..30

M

MerchantID, assigned by Computop. Additionally this parameter has to be passed in plain language too.

PayID

an32

M

ID assigned by Paygate for the payment to be captured

TransID

ans..64

M

TransactionID provided by you which should be unique for each payment

MAC

an64

M

Hash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here:

Amount

n..10

M

Amount in the smallest currency unit (e.g. EUR Cent). Please contact the Computop Helpdesk, if you want to capture amounts <100 (smallest currency unit).

Currency

a3

M

Currency, three digits DIN / ISO 4217. Only CHF and EUR permissible. Please find an overview here: A1 Currency table

ReqId

ans..32

O

To avoid double payments or actions (e.g. by ETM), enter an alphanumeric value which identifies your transaction and may be assigned only once. If the transaction or action is submitted again with the same ReqID, Computop Paygate will not carry out the payment or new action, but will just return the status of the original transaction or action.

Please note that the Computop Paygate must have a finalized transaction status for the first initial action (authentication/authorisation). This does not apply to 3-D Secure authentications that are terminated by a timeout. The 3-D Secure Timeout status does not count as a completed status in which the ReqID functionality on Paygate does not take effect. Submissions with identical ReqID for an open status will be processed regularly.

Notice: Please note that a ReqID is only valid for 12 month, then it gets deleted at the Paygate.

Parameters for captures with PostFinance Pay

The following table describes the result parameters with which the Computop Paygate responds to your system

pls. be prepared to receive additional parameters at any time and do not check the order of parameters

the key (e.g. MerchantId, RefNr) should not be checked case-sentive

KeyFormatCNDDescription

mid

ans..30

M

MerchantID, assigned by Computop

PayID

an32

M

ID assigned by Paygate for the payment, e.g. for referencing in batch files as well as for capture or credit request.

XID

an32

M

ID for all single transactions (authorisation, capture, credit note) for one payment assigned by Paygate

TransID

ans..64

M

TransactionID provided by you which should be unique for each payment

Status

a..50

M

OK (URLSuccess) or FAILED (URLFailure)

Description

ans..1024

M

Further details in the event that payment is rejected. Please do not use the Description but the Code parameter for the transaction status analysis!

Code

an8

M

Error code according to Paygate Response Codes (A4 Error codes)

Response parameters for captures with PostFinance Pay

Credit with reference

Credits (refunds) are possible via a Server-to-Server connection. For a Credit with reference to a capture the amount of the Credit is limited to the amount of the previous capture. To carry out a credit with a reference transaction, please use the following URL:

https://www.computop-paygate.com/credit.aspx

Notice: For security reasons, Computop Paygate rejects all payment requests with formatting errors. Therefore, please use the correct data type for each parameter.

The following table describes the encrypted payment request parameters:

KeyFormatCNDDescription

MerchantID

ans..30

M

MerchantID, assigned by Computop. Additionally this parameter has to be passed in plain language too.

PayID

an32

M

ID assigned by Paygate for the payment to be credited

TransID

ans..64

M

TransactionID provided by you which should be unique for each payment

Amount

n..10

M

Amount in the smallest currency unit (e.g. EUR Cent). Please contact the Computop Helpdesk, if you want to capture amounts <100 (smallest currency unit).

Currency

a3

M

Currency, three digits DIN / ISO 4217. Only CHF and EUR permissible. Please find an overview here: A1 Currency table

MAC

an64

M

Hash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here:

ReqId

ans..32

O

To avoid double payments or actions (e.g. by ETM), enter an alphanumeric value which identifies your transaction and may be assigned only once. If the transaction or action is submitted again with the same ReqID, Computop Paygate will not carry out the payment or new action, but will just return the status of the original transaction or action.

Please note that the Computop Paygate must have a finalized transaction status for the first initial action (authentication/authorisation). This does not apply to 3-D Secure authentications that are terminated by a timeout. The 3-D Secure Timeout status does not count as a completed status in which the ReqID functionality on Paygate does not take effect. Submissions with identical ReqID for an open status will be processed regularly.

Notice: Please note that a ReqID is only valid for 12 month, then it gets deleted at the Paygate.

Parameters for credit payments with PostFinance Pay

The following table describes the result parameters with which the Computop Paygate responds to your system

pls. be prepared to receive additional parameters at any time and do not check the order of parameters

the key (e.g. MerchantId, RefNr) should not be checked case-sentive

KeyFormatCNDDescription

mid

ans..30

M

MerchantID, assigned by Computop

PayID

an32

M

ID assigned by Paygate for the payment, e.g. for referencing in batch files as well as for capture or credit request.

XID

an32

M

ID for all single transactions (authorisation, capture, credit note) for one payment assigned by Paygate

TransID

ans..64

M

TransactionID provided by you which should be unique for each payment

Status

a..50

M

OK (URLSuccess) or FAILED (URLFailure)

Description

ans..1024

M

Further details in the event that payment is rejected. Please do not use the Description but the Code parameter for the transaction status analysis!

Code

an8

M

Error code according to Paygate Response Codes (A4 Error codes)

Response parameters for credit payments with PostFinance Pay

Reversal

Authorisation reversals may be initiated, if the merchant has received a fault message during authorisation or did not receive a response after a certain period, so that it is not clear whether the authorisation has been successful. Authorisation cancelations may only be sent, if the affected transaction has not been submitted for capturing yet. Please be informed that partial reversals are not allowed, only the full amount of the transaction can be reversed.

Reversals are possible via a Server-to-Server connection. In order to cancel a payment via a server-to-server communication, please use the following URL:

https://www.computop-paygate.com/reverse.aspx

Notice: For security reasons, Computop Paygate rejects all payment requests with formatting errors. Therefore, please use the correct data type for each parameter.

The following table describes the encrypted payment request parameters:

KeyFormatCNDDescription

MerchantID

ans..30

M

MerchantID, assigned by Computop. Additionally this parameter has to be passed in plain language too.

PayID

an32

M

ID assigned by Paygate for the payment to be reversed

Amount

n..10

M

Amount in the smallest currency unit (e.g. EUR Cent). Please contact the Computop Helpdesk, if you want to capture amounts <100 (smallest currency unit).

Currency

a3

M

Currency, three digits DIN / ISO 4217. Only CHF and EUR permissible. Please find an overview here: A1 Currency table

TransID

ans..64

M

TransactionID provided by you which should be unique for each payment

MAC

an64

M

Hash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here:

UserData

ans..1024

O

If specified at request, Paygate forwards the parameter with the payment result to the shop.

ReqId

ans..32

O

To avoid double payments or actions (e.g. by ETM), enter an alphanumeric value which identifies your transaction and may be assigned only once. If the transaction or action is submitted again with the same ReqID, Computop Paygate will not carry out the payment or new action, but will just return the status of the original transaction or action.

Please note that the Computop Paygate must have a finalized transaction status for the first initial action (authentication/authorisation). This does not apply to 3-D Secure authentications that are terminated by a timeout. The 3-D Secure Timeout status does not count as a completed status in which the ReqID functionality on Paygate does not take effect. Submissions with identical ReqID for an open status will be processed regularly.

Notice: Please note that a ReqID is only valid for 12 month, then it gets deleted at the Paygate.

Parameters for reversals with PostFinance Pay

The following table describes the result parameters with which the Computop Paygate responds to your system

pls. be prepared to receive additional parameters at any time and do not check the order of parameters

the key (e.g. MerchantId, RefNr) should not be checked case-sentive

KeyFormatCNDDescription

mid

ans..30

M

MerchantID, assigned by Computop

PayID

an32

M

ID assigned by Paygate for the payment, e.g. for referencing in batch files as well as for capture or credit request.

XID

an32

M

ID for all single transactions (authorisation, capture, credit note) for one payment assigned by Paygate

TransID

ans..64

M

TransactionID provided by you which should be unique for each payment

Status

a..50

M

OK (URLSuccess) or FAILED (URLFailure)

Description

ans..1024

M

Further details in the event that payment is rejected. Please do not use the Description but the Code parameter for the transaction status analysis!

Code

an8

M

Error code according to Paygate Response Codes (A4 Error codes)

Response parameters for reversals with PostFinance Pay

Paygate

Documentation (EN)

Dokumentation (DE)

Paygate Status