The Xero API has a call limit of 5000 per day with no more than 60 in any one minute. Each invoice requires 3 calls, and each stock item that is being synced will require 3 - 4 calls so it is essential to manage large volumes of data. Attempting to exceed the API limit will result in throttling.

The limited number of  tracked stock items that Xero can hold is dependent on the type of account the customer has. It must be noted that once a stock item has been marked as a tracked stock item in Xero, it can no longer be changed. The implications of this must be considered before enabling this option.