Skip to main content
OnzliOnzli
Help
Browse Onzli help
Understanding tax classification and preview results

VAT preview

A read-only look at how your invoices are classified into the VAT boxes.

Last reviewed 25 October 2026

The VAT preview reads your ERPNext invoices, read-only, and shows how they would be classified into the VAT boxes. Nothing is filed, stored as a return or changed.

The preview is a switch the service operator can turn on. If you do not see Preview from ERPNext (read-only) on the VAT Returns page, it is not switched on for your service.

Run a preview

  1. Go to VAT Returns and choose Preview from ERPNext (read-only).
  2. Choose the From and To dates.
  3. Choose Preview.

What you will see

  • A banner reminding you this is a preview.
  • Classified figures by box, next to the figures from the existing calculation where there is one, with a status for each box and any differences.
  • Source totals read from ERPNext.
  • Tax codes and their treatment. The decision for each template, or undecided: blocks, with a form to record one. See Record what a tax template means.
  • Exceptions and blocked items. Anything that blocks the figures is marked blocks; other notes are marked note.
  • Left out of every box. Items deliberately excluded, with the reason and the rule applied.
  • Provenance. Every classified amount traced back to its source invoice line.

If any blocking item exists, the classified figures are withheld until it is resolved.

Keep a copy

Choose Download preview (JSON) to save the result.

A preview is not a return. To create one, use New calculation on the VAT Returns page. See Preview, approve and submit.

Record what a tax template means

Tell Onzli once how each ERPNext tax template is treated for VAT.

Preview, approve and submit: the difference

What each stage means, and the point at which anything reaches HMRC.

Source exceptions

What to do with an item Onzli could not place in any VAT box.