I am using the Python Client to amend a Google Sheet shared to a Google Service Account. Everything works as expected when using a Sheet that is created by the Service Account, but returns a Requested entity was not found error when accessing a Google Sheet that is owned by someone else but shared with the service account. I have tried with all combinations of these definitions: Personal Google account (i.e. @gmail.com) Workspace Google account Service Account with "shared outside domain set" with Drive and Sheets APIs enabled "Stock" Service account with Drive and Sheets APIs enabled Shared the containing folder of the Sheet Shared just the Sheet itself Can anyone point to what I could be doing wrong that would mean that the client can find a sheet that it creates, but not one that is shared with it? Continue reading...