i.MAS and SAF-T in Lithuania
Lithuania operates i.MAS, the smart tax administration system managed by the State Tax Inspectorate, VMI. i.MAS includes separate modules for VAT invoice register reporting, transport document reporting, and on-request accounting data submission.
i.MAS has three main parts, which are called i.SAF, i.VAZ and i.SAF-T.
- i.SAF invoice data: This XML electronic register of sales and purchase invoices is submitted monthly by the 20th of the month following the reporting period. All VAT-registered businesses must complete the submission.
- i.VAZ transport/consignment document: XML data supporting documents for domestic movements of goods by road.
- i.SAF-T: Accounting transaction reporting for Lithuanian resident legal entities that fall within the applicable SAF-T scope. Currently, it is required only on demand by the tax authority, VMI.
i.SAF
i.SAF: All taxable persons registered for VAT must submit i.SAF, data on VAT invoices issued and received under their Lithuanian VAT number, to the Tax Authority’s system.
It is submitted in XML format on a monthly basis by the 20th day of the following month.
i.SAF is a recurring VAT invoice register reporting obligation. It is not the same as i.SAF-T and should not be described as a general e-invoicing mandate.
SAF-T or i.SAF-T
SAF-T, or i.SAF-T, covers accounting transaction reporting for Lithuanian resident legal entities that fall within the applicable SAF-T scope. This is mandatory only on request.
i.SAF-T is not a routine monthly or annual submission. It is an on-request audit file used to provide structured accounting data to VMI when required under the applicable audit or control process.
i.SAF (Mandatory)
Header
The header consists of the general information on the person whose registers are provided, tax period, file type, etc.
Master File
The master file consists of data from registers of issued and received VAT invoices that are linked to the data of source documents by the unique code of the buyer and/or supplier used in the accounting system of the entity. The completion of the master file is recommended when multiple VAT invoices with the same buyer or supplier are registered over the tax period. The master file may not be entered, but in that case, the register data of buyers and suppliers must be presented in the data of source documents.
Source Documents
The data of source documents consist of the data from registers of received and issued VAT invoices and payment details. The data of source documents may not be entered if no VAT invoices were received or issued during the tax period (in that case only the header of i.SAF data file shall be filled in). The provision of payment details shall be recommended when the entity wishes to use a preliminary VAT return preparation service.
SAF-T (On-request)
SAF-T files can be submitted fully or in divided versions.
The detailed structure, permitted data groups, and file division rules are defined in the official technical specification. Businesses should maintain accounting data in a format that supports extraction of the required i.SAF-T data when requested by VMI.
i.MAS, i.SAF, i.VAZ and i.SAF-T
These three modules serve different compliance purposes:
- i.SAF covers monthly VAT invoice register reporting.
- i.VAZ covers transport or consignment document reporting for domestic road movements of goods.
- i.SAF-T covers structured accounting data reporting on request.
Lithuania should therefore be described as having recurring i.SAF VAT invoice register reporting and on-request i.SAF-T audit file requirements, rather than a single periodic SAF-T reporting obligation.
How Can SNI Help You?
The SNI SAF-T Lithuania solution is designed to support businesses in meeting Lithuania’s i.SAF-T reporting and tax audit requirements. The solution is equipped with customizable tables that capture the necessary accounting and transaction data required by the Lithuanian tax authority. These tables can be mapped and configured according to your ERP system and business needs, ensuring seamless integration with local compliance standards. By using this configuration, the solution enables the generation of structured reports in the prescribed XML format, supporting compliance with Lithuania’s SAF-T requirements. All generated reports are conveniently collected and displayed in a user-friendly cockpit, making it easier to manage, review, and track compliance activities. With the SNI SAF-T Lithuania solution, your business can stay fully prepared for Lithuanian SAF-T obligations.