How Kontala works out your figures

How Kontala turns your transactions into the figures on your VAT return.

Last updated 10 July 2026.

Every figure Kontala shows comes from your own transactions. Here is how it gets there.

From transaction to box

  1. Read. Kontala imports your transactions from your connected sources.
  2. Categorise. Each one is classified - a sale, a purchase, an expense - and its VAT treatment worked out.
  3. Total. Kontala adds the VAT on sales into Box 1, the reclaimable VAT on purchases into Box 4, and net sales into Box 6.

Why a figure might not match your expectation

  • Uncategorised or flagged transactions are held back until you resolve them, so they are not yet counted.
  • Corrections you make at the source flow straight through and recalculate the affected boxes.
  • The period matters - only transactions dated within the VAT period are included.

If something still looks wrong, see Why my figures look different.