Error applicationId and/or locationId is incorrect

I’m building a web application payment form in PHP and Javascript using a lot of the code you supplied in SDK documentation. I have it working fine in Sandbox mode, but when I switched it over to Production mode I get the above error.

I’ve double-checked that I’m using the correct production applicationId and locationId from the client’s Square dashboard. I’ve got the javascript printing it correctly to the console immediately before I make the call to window.Square.payments( appId, locationId ) so I know the two values being passed to that method are correct. Nevertheless, it returns undefined and gives me the above error.

I’ve only seen one other query in this form along these lines and didn’t find that conversation helpful at all.

Any clues at all as to what I might be doing wrong?

When you switched to production did you also update the domain string in the JavaScript reference from to ? :slightly_smiling_face: