Test environment - "Invalid paRes from issuer" for Adyen test cards


Test environment

We get "Invalid paRes from issuer" when sending back the MD/PaRes/PaymentData. 

We use 4212 3456 7890 1237, 03/30, 737 and then user/password

I presume Adyen is the issuer of this test card? 


  • Official comment

    Hi Matt,

    Adyen is the "issuer" for the test cards you can use on the test environment. On Test, this most often occurs when the paRes isn't valid base64. You should very rarely ever get this on live, and would be indicative of issues with the issuer. Our error documentation has more information.

    Take a look at the paRes right before you send it to Adyen and ensure it is valid base64. You can look for things like correct url decoding from the query parameter, that invalid characters weren't introduced like no backslashes.


  • We're pretty sure it's correct. We do the same with another gateway.

    I can fetch this, parse it JSON, base64 decode, zlib deflate it, and load it into a XML document.


    I think there is something account specific here and then error is a general catch all (as someone else - Tolo company or something like - observed if you google exact error message)

  • Okay paRes is fine, for others, the error message blinded us into looking at paRes and trying all sorts of alternative encoding, json escaping etc.. when all was fine with paRes. 

    "Invalid paRes from issuer" actually means "Invalid paRes or MD from issuer", in our case we overlooked that we were using the original MD instead of the one posted back to us


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