Invoice numbering in Lithuania: series, number and the rules

A Lithuanian invoice must carry a series and a number. You choose the series yourself, from letters or digits; the number must be formed in ascending sequence; and the same number may not appear on two invoices within the same series.

This is set out in the Rules approved by Government Resolution No. 780: point 6 applies to the ordinary invoice (sąskaita faktūra) and point 12 to the VAT invoice (PVM sąskaita faktūra).

The legal texts we read prescribe no format: no number of digits, no hyphen between series and number, no year in the series. For the VAT invoice the Law on VAT adds that the series and number must allow the invoice to be identified.

Example: three invoices issued in a row

This is an invented example: the names and codes are not real. Vardenis Pavardenis is self-employed under a Lithuanian individual activity certificate (individualios veiklos pažyma), is not a VAT payer and uses a single series, "SF". In September he issues three invoices. Each names the seller as Vardenis Pavardenis, individual activity certificate No. 000000.

The number does not depend on the buyer: two buyers, one sequence. There is no VAT because the seller is not a VAT payer, so the total is quantity multiplied by price. You can prepare such an invoice with our free invoice tool: you type in the series and number, and the tool shows whether any required information is missing.

What does Lithuanian law say about the series and number?

Point 6 of the Rules for issuing and recognising accounting documents used to calculate taxes says that an invoice must have a series and a number, and gives three requirements:

1. The number must be formed in ascending sequence (point 6.1).
2. The number must be based on one or more series which, at the choice of the business, may be composed of letters or of digits (point 6.2).
3. The business must ensure the number is unique: different invoices may not show the same number based on the same series (point 6.3).

Point 12 repeats these requirements for the VAT invoice. In addition, Article 80(1)(2) of the Law on VAT lists among the required information "the series and number of the VAT invoice which allow the VAT invoice to be identified".

What can an invoice series look like?

Three schemes that fit the wording of the Rules:

Every series is another sequence to look after, so one series leaves fewer chances for a mistake.

Do invoice numbers have to run without gaps?

The Rules say "in ascending sequence" (didėjančia seka). The words "without gaps" or "consecutive" do not appear in the texts we read, and those texts do not say directly that a later number must carry a later date.

What if a number was skipped or used twice?

A repeated number within the same series directly contradicts point 6.3 (point 12.3 for the VAT invoice). These rules contain no procedure for correcting such a mistake.

Article 7(5) of the Law on Financial Accounting sets a general rule: accounting documents that support transactions carried out in money may not be corrected; if a mistake is made, a new accounting document is prepared, and the document with the mistake is treated as invalid and kept together with the other accounting documents of the reporting period.

Whether and how this applies to an invoice already sent to the buyer is a question for an accountant.

Paper documents have their own rule. Under point 31, a paper document spoiled while being issued is marked at once with the word „Anuliuota“ (cancelled) and the date of cancellation, and the person who issued it confirms the cancellation with a signature. It is kept for the retention periods set by the Chief Archivist of Lithuania.

A skipped number. The texts we read do not describe what to do after skipping a number. Do not renumber invoices you have already issued, note in your list which number was not used and why, and speak to an accountant.

A different case is a change in the taxable amount or quantity, a discount or a return of goods after the invoice is issued. Article 83(1) of the Law on VAT provides that such changes are documented by a credit note issued by the person who issued the original document or, if the parties agree, by a debit note issued by the buyer, provided the buyer is a VAT payer.

See the guide to credit and debit notes. Under paragraph 3 of that article, such a document states the date of issue, series and number of the VAT invoice being adjusted, where it is possible to establish exactly which document that is.

Do you have to restart invoice numbering in the new year?

The texts we read do not tie numbering to the calendar year and do not require starting from the first number in a new year. A continued sequence meets the Rules, because the numbers keep ascending and do not repeat: SF No. 047 in December, SF No. 048 in January.

To start the year from 001, choose a new series. Restarting the same series would put two identical numbers in it, which points 6.3 and 12.3 forbid. This is our conclusion from the wording of those points; they have no separate provision about the start of a year.

How to keep the sequence without software

Point 7 obliges businesses to keep records of the invoices they receive and issue. Article 78(5) of the Law on VAT obliges taxable persons to keep registers of the VAT invoices they receive and issue; the requirements for those registers are set by the central tax authority (the State Tax Inspectorate).

We do not examine those requirements here, so confirm the form and deadlines for your case with an accountant.

A few habits keep the sequence in order. They are practical suggestions, not legal requirements:

1. Keep one list (a notebook or a spreadsheet) with one row per invoice: series, number, date, buyer, amount.
2. Before issuing an invoice, look at the last row and add the new one, and only then fill in the document.
3. Write the number with leading zeros, 001 rather than 1, so that files sort in the right order.
4. Name the file after the series and number, for example "SF-016". Two files with the same name show a repeat at once.
5. If several people issue invoices, each can have a separate series so that the numbers do not collide.

The guide to the self-employed invoice has an example with all the required information.

What our tool does and does not do

The invoice tool is free, needs no registration and keeps the draft in your browser. It covers the ordinary invoice and the VAT invoice with rates of 21%, 12%, 5% and 0%, shows which required information is missing, and prints or saves a PDF through the browser's print window.

It is not accounting software. It keeps no register, sends nothing to the State Tax Inspectorate and does not increase the number for you, so you enter the series and next number from your own list. It does not cover reverse charge, margin schemes, or credit and debit notes.

This guide explains what the legal texts say and is not tax advice. If your numbering already contains a mistake, or you are changing the scheme mid-year, decide with an accountant.