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Canada Post API create label error - "Contract Number is a required field.\r\n"


I'm trying to create a label with the carrier Canada Post via API, but after i enter all the relevant fields for the api call the system returns a 500 error response:


 "Message""An error has occurred.",
    "ExceptionMessage""Contract Number is a required field.\r\n",
This is a weird error because it is not in shipstation docs and i'm not sure what to pass as a parameter even though i have the contract number.
Has anybody had this same issue before?

New Contributor

Just wanted to say that yes, I have had this issue persistently the only workaround was to get OneBalance but now that we have a credit account I would greatly prefer to use the standard Canada Post. Has anyone solved this? 

Hi @anxvtg


Thanks for being a part of our community and for your comment. I see that you were able to reach out to our support team about this and get some answers. 


 Just for community knowledge, this error can occur because of a mismatch of account types. If anyone else is seeing this error message I would first recommend reaching out to our support team, as there are some troubleshooting steps we can assist with when attempting to remove and re-add the account. 


-Erin: Your Friendly Neighborhood ShipStation Community Manager 


Hi Erin,

I have this same error and reached out to your Shipstation support as you've specified, but they told me to contact Canada Post. Can you please provide details on what can be done to resolve this.

I have tried adding and removing our Canada Post account multiple times and nothing works.