Thanks for your information Craig.
If you polling the result by POST the Form Recognizer Analyze API , it's actually call the API again and there will be fees applying for it.
URL request for this case: https://{endpoint}/formrecognizer/v2.1/prebuilt/receipt/analyze[?includeTextDetails][&locale][&pages]
The fee for it is as below screenshot:
If you polling the result by "GET" the analyze result, it will not re-analyze the document so there is no fee for it. We recommend calling this operation no more than once a second.
URL request for this case: https://{endpoint}/formrecognizer/v2.1/prebuilt/receipt/analyzeResults/{resultId}
Hope this helps! Please let me know if you have more questions.
Please kindly accept the answer if you feel helpful, thank you.
Regards,
Yutong