Integration partners can retrieve the estimated transaction fee via accountingItems/getAll, with CreditCardTransaction extent.

The "Fee" parameter gives the estimated transaction fee value. (https://mews-systems.gitbook.io/connector-api/operations/finance#credit-card-transaction)

However, with the recent feature release of transaction fee adjustments for select properties, the updated fees are not returned, and can cause discrepancy between data in Mews PMS and in other systems (e.g. accounting, business intelligence, etc).

In the exported Payment Report, "Fee total net"/"Fee total" refers to the estimated transaction fee and will be displayed "Fee" parameter in the CreditCardTransaction object. On the other hand, "Adjusted total fee" in the same report refers to the actual transaction fee (updated after 3 days) and is currently not returned in the API response.

https://help.mews.com/en/articles/4682847-track-your-fees-with-the-payment-report-export