Corrections and Recalculations

When you change something in the form, the server recalculates the findings and offers corrections. The form itself does not perform any calculations, it simply inputs what it receives back.

What Is Recalculated

• The tax base as the sum of items (for a receipt the total amount, since it contains item prices with tax).
• The total amount as the base plus tax.
• Tax as the difference between the total amount and the base.
• Missing item prices from the quantity and unit price.

A correction is offered only when it would change something. If the VAT summary reveals which of the three summary fields has been read incorrectly, only that one will be offered for correction.

What Is Automatically Corrected

Almost nothing. The only exception is the total amount, and only if it is contradicted by two different parts of the document at once: the VAT summary and the sum of the items. Such high certainty mainly occurs in final settlements with advances, where the model sometimes writes an overpayment into the total amount after deducting advances instead of the sum of the document. In all other cases, the value is simply offered and you must input it.

The second such correction is a missing VAT rate for an item. Discounts, rounding, or the deduction of an advance often have a dash instead of a rate on the document. If the document has a single rate, it gets filled in — and whether that line applies or is zero is decided by the document's summary: the value is inputted that makes the recalculated tax match the amount stated by the document. For documents with multiple rates, nothing is filled in.

The third is the amount of tax recorded instead of the rate. Foreign invoices may have an amount in crowns or euros in the column labeled "VAT," instead of a percentage, and the rate is only found in the summary below the table. This is recognized by the fact that such a rate is nowhere valid and upon reading, the rate that applies is derived from it — and even then, the correction is made only if the recalculated tax matches the document.

The fourth involves item prices with VAT on the invoice. Invoice lines are maintained without tax in our system — thus the export to accounting calculates tax onto the base. If the model writes amounts with tax into the lines, it can be recognized by the fact that their sum matches the payable amount instead of the tax base, and the lines are recalculated. This is done only if the sum after recalculating to the base truly matches; otherwise, nothing is changed, and the finding on the sum of the items remains. On receipts, prices with tax are correct and are not recalculated.

Tolerance

Rounding is not an error. The document is calculated to the haler, printed rounded, and the accounting program calculates the amounts in its way. Tolerance is governed by currency: for crowns, totals are compared in whole crowns, and for euros, in cents. The sum of items against the base has a tolerance of two percent, because discounts outside of items and rounding of individual lines accumulate over dozens of items. Line arithmetic tolerates half a percent.

The read figure additionally changes the amount by an order of magnitude, so even the loosest tolerance will still catch it.

VAT Rates

The rate check knows Czech rates over time, so a receipt from 2017 with 15% for food is not flagged. The date of issue is taken with a fifteen-day allowance, as a tax document is issued only after the performance.

Documents from abroad are assessed more loosely. It is not reliably determinable in which country the document is taxed: a Slovak or Polish e-shop charges a Czech customer 21%, a highway vignette is taxed in Austria, and one ticket may show Portuguese 6% next to Czech 21%. Therefore, for documents with a foreign VAT number, it only monitors whether such a rate exists anywhere. A recorded amount of tax instead of a percentage will still get flagged, but a usual foreign rate will not trigger a finding.

A zero rate is always fine, regardless of whether it is an exempt transaction or a transferred tax liability.

Rounding and Advances on the Document

Lines that change the payable amount — paid advances, discounts, rounding — are recorded by the model among the items to keep the document complete. The deduction has a negative amount. If such a line is missing and the sum does not match, please add it manually.

The item sum check includes these: it first compares the sum of all items with the tax base, and if it does not match, it tries once more without deductions. Thus, for final settlements with advances, no findings will arise. This does not apply to credit notes, where all items and the base are negative.

When the Recalculation Does Not Match the Paper

It happens, and almost always because the supplier calculates tax differently — from unit prices after rounding, or conversely from the base for the entire item. The difference usually lies in halers.

In such cases, keep the value from the document and confirm the finding upon acceptance. What is on paper is decisive; our calculation is a check, not the truth.