Each DTE must contain a folio number, which is a unique identifier under the control of the SII.

The supplier must request a folio range through the SII web portal. The size of the folio range is determined by the SII based on the historical volumes reported by the company. As a result of the folio range request, the SII returns a folio authorization. For each type of DTE, the supplier must request a separate folio range from the SII. For example, the DTE invoice gets its own folio range, while the DTE credit note gets another.

Folio numbers have an expiration date. A given folio may be skipped due to technical problems caused by errors in its issuance. Unused folio numbers must be reported to the SII as anulados (canceled).

All folio management is done manually in the taxpayer's account on the SII website using an authorized and valid digital certificate.

It is the supplier's responsibility to upload the folio ranges assigned by the SII to the Sovos portal, so that Sovos can assign a folio number to each DTE issued.