Known limitations

One VAT rate per event. Every line is invoiced at the single configured rate. An event selling items at different rates fails issuance (visibly) rather than mis-invoicing. A per-rate mapping is not implemented yet.

Partial refunds have no credit note. Both providers can only credit a document's full value. A partial refund issues nothing until refunds reach the full amount; you can issue a full credit note by hand.

Duplicate client records stop issuance (Fact.pt). If a NIF matches several clients in Fact.pt, clean them up in the Backoffice and retry.

Fact.pt client data is overwritten. When a client is created/updated from an order, the order's address replaces the one on file for that NIF.

Switching providers mid-event doesn't re-issue. Old documents stay with the provider that issued them, and can no longer be downloaded through pretix.

No bulk issuance. Issuance by hand is one order at a time, on purpose. For a backlog, loop the task from a shell:

# python -m pretix shell
from django_scopes import scopes_disabled
from pretix.base.models import Order
from pretix_ptinvoicing.tasks import issue_invoice

with scopes_disabled():
    for order in Order.objects.filter(event__slug="my-event", status=Order.STATUS_PAID):
        issue_invoice.apply(kwargs={"order_pk": order.pk, "event_pk": order.event.pk})

Orders already issued successfully are skipped.