Status of Export

Possible methods:

Filter on modification date with Odata
Store the processed OrderID's in your application. This allows to check which orderID is new and not processed yet.
Store the status in a field in Billit (via a Patch command) This is explained below.

Value that can be updated:

Property "Is Sent".
Possible value are true or false. Default value is false.
Is not displayed in the My Billit Interface (cannot be modified by users).
Update via a Patch of the OrderID : Patch https://api.sandbox.billit.be/v1/orders/1571999 : set "IsSent" status to true.

Content of the Patch command:

{
    "IsSent": true 
 }

When we request list of items still to be processed, we can include with Odata a filter based on the filter IsSent = false.
Example: GET https://api.sandbox.billit.be/v1/orders?$filter=OrderType+eq+'Invoice'+and+OrderDirection+eq+'Cost'+and+LastModified+ge+DateTime'2025-04-23'+and+IsSent+eq+false
So the invoices you just have patched will not be in the list anymore.

FYI Other related fields that can also be patched:

Internal Info : add free text
Approval Status : do only use when approval is activated. Possible values are Approved / Pending / Rejected.