Supplementary control statement

What it means

A supplementary control statement is a VAT control statement that a taxpayer files after the deadline on discovering that data in the original statement were missing or wrong. Before the deadline, a corrective statement is filed instead, fully replacing the original one.

The control statement contains invoice-level data, which the tax authority automatically matches between suppliers and customers. If someone omits an invoice or enters the wrong amount, the system flags a mismatch and the taxpayer may receive a request for an explanation.

A supplementary statement is often linked to an amended VAT return, for example when a purchase invoice turns up late. That is not always the case: sometimes only a detail in the statement changes, such as the customer's VAT number, and the VAT return remains correct.

How it works in practice

A supplementary control statement contains only the data being added or corrected, not the whole statement again. When a record is corrected, the original data are usually reported with negative values and the new data with positive ones, so the tax authority can see what changed.

The most common reasons are late invoices, wrong VAT numbers, incorrect supply dates or mixed-up lines under the reverse charge. Regular reconciliation with suppliers and checking mismatch notices in the electronic mailbox help catch errors earlier.

If the tax authority asks for a mismatch to be resolved, the taxpayer must respond within the deadline or face a penalty. An explanation is often enough; sometimes a supplementary statement is needed, and repeated mismatches increase the risk of a tax audit.

What to watch out for

Failing to file or reporting wrong data in a control statement can lead to fines that become significant if repeated. Filing a supplementary statement voluntarily before the tax authority finds the error is generally better, and in some cases a waiver of the penalty can be requested.

A supplementary statement is not filed for a change that belongs to a different period. For example, a tax base correction for a credit note is reported in the period when the correction is made, not retrospectively in the original month, so it is always necessary to assess where the change belongs.