Last updated: 2026-09-05
It can also be called a primary document. It is a document that certifies the existence of an economic transaction (the fact that an economic transaction has taken place).
The document may be prepared in electronic or paper form (paper form is used less and less). The document is prepared in such a way that the information contained in it does not disappear during its entire storage period and that it is possible to create a derivative (copy) of this document.
For example, a credit institution charges a bank commission (the source document is a bank statement or payment order), a company purchases goods from another company (the source document is a tax invoice, delivery note or other goods delivery document).
In order for a document to be used as an accounting source document, the respective document must contain certain mandatory details and information.
On the basis of source documents, the accountant records (posts) transactions in the accounting records. Entries in the accounting records are not allowed if their content or measurements differ from those in the source document.
If a document does not meet certain requirements, then the accountant has no right to post the transaction, even if the transaction has actually taken place.
For example, the company’s manager or an employee buys office supplies necessary for the company’s operations in a shop. Payment is made in cash and the purchase value excluding VAT is 30 euros or more. The electronic cash register receipt does not contain data about the buyer and no other document with the necessary particulars is attached to the receipt. There is no basis to regard such a document as a source document. To resolve the situation, a receipt or another document with the missing particulars should be attached to the cash register receipt, and the transaction should be confirmed in accordance with the procedure specified by the manager.
Source documents are also necessary in order to:
For accounting purposes, not every source document in itself needs to have legal force. A document needs legal force if it is used to certify or establish the rights and obligations of persons.
The Law on the Legal Force of Documents determines which particulars must be included for a document to have legal force. In turn, the Accounting Law also provides for cases where the source documents listed in paragraphs 7 and 8 of Article 11 may be used in accounting without a signature, if the existence of the economic transaction is certified by another document or the transaction is certified in accordance with the procedure specified in another law.
For example, an invoice received by the company without a signature may, in certain cases, be a source document if the existence of the transaction indicated in the invoice is substantiated by another external document that has legal force, or if the existence of the transaction and the correctness of the information provided in the invoice are certified by a responsible person in accordance with the procedures established by the company.
If a document is signed on behalf of a limited liability company (SIA) by a natural person, it must be ensured that this person has the right to represent the LLC and to sign the specific document. Usually, an LLC is represented by the management board, but representation rights may also be granted to another person, for example, by a power of attorney.
It must also be checked whether legal acts, the LLC’s articles of association or other binding documents do not set restrictions regarding the signing of the specific document or the performance of the transaction.
This is important when handing over goods to another person. For example, if the goods are received on behalf of the buyer’s company by a person who does not have the right to represent this company, a dispute may arise as to whether the goods have actually been delivered to the buyer. Therefore, when issuing goods, it is important to identify the recipient of the goods and ensure that they have the right to receive them on behalf of the buyer.
The document must be created in a physically durable manner and in such a way that it cannot easily be technically altered. For example, the document must not be (hand)written in pencil. The document must be prepared so that throughout its storage period the information contained in the document does not disappear. The preservation of the information contained in the document also depends on the conditions under which the documents are stored (for example, documents should not be stored in premises where increased air humidity is possible). In relation to the storage of electronic documents, it is necessary to create and regularly update backup copies of the data.
A source document must contain the particulars and information on the economic transaction as laid down in the Accounting Law.
| What must be indicated | Notes |
|---|---|
| Type of document | The name of the type of document, for example, invoice, receipt, voucher or report. |
| Date | The date on which the document was prepared. |
| Number | The serial number of the document or another unique identifier. |
| Parties to the transaction | The names of the author of the document and other parties to the economic transaction or their given names and surnames. An economic transaction is considered to be a legal transaction as a result of which a change in value takes place (for example, one party transfers a certain good (value) to the other party). |
| Registration data | The registration numbers or taxpayer registration codes of the author of the document and other parties in the economic transaction. |
| Transaction | Information on the economic transaction. What has been sold, received or provided, as well as the value of the transaction expressed in money. |
| Signature | The signature of the person responsible for the correctness of the information provided in the document, if a signature is required in the specific case. |
If the document is a VAT invoice, it must additionally comply with the requirements of the Value Added Tax Law.
A VAT invoice must also indicate the information specified in the VAT Law. The requirements differ depending on the type of transaction.
| What must be indicated | Notes |
|---|---|
| Invoice date and number | The date of issue of the invoice and its serial number. |
| Seller’s data | Name, legal address and VAT payer’s registration number. |
| Buyer’s data | Name, legal address and VAT payer’s registration number, if required. |
| Transaction date | The date of delivery of the goods or provision of the service, if it differs from the date of issue of the invoice. |
| Information on goods or services | The name of the goods or service, quantity, unit of measure and unit price (excluding VAT). |
| Discounts | Granted discounts, if they are not already included in the unit price. |
| VAT rate | The VAT rate applied to the transaction. |
| VAT amount | The calculated VAT amount. |
| Transaction value | The total value of the transaction excluding VAT and the total amount including VAT, insofar as required by the applicable rules. |
Depending on the type of transaction, additional information may also have to be indicated in the VAT invoice. For example, a note on reverse charge VAT, application of the 0 % VAT rate or exemption, self-assessment or application of a special VAT regime.
It is permitted not to include a signature in a source document in the following cases (paragraphs 6–8 of Article 11 of the Accounting Law):
These documents (without a signature) do not have legal force, but they are valid for entries in accounting.
An electronic source document must contain all mandatory particulars. An electronic document is considered to be signed by hand if it has a secure electronic signature or an electronic signature and the parties have agreed on this in writing (agreement on paper or signed with a secure e-signature).
A secure e-signature can be obtained using an ID card (with activated e-signature certificates), the eParaksts mobile application and other means.
An external source document is also considered to be:
Condition: the existence of the transaction is certified by the responsible person of the recipient of the document in accordance with the procedure specified by the manager (paragraph 10 of Article 11 of the Accounting Law).
In accounting, the unit of value is the euro (Article 7 of the Accounting Law). The foreign exchange rate used in accounting is the euro reference rate published by the European Central Bank. If there is no euro reference rate published by the European Central Bank for a particular foreign currency, a rate against the euro published by a recognised provider in the global financial markets is used.
If the values in the source document are not indicated in euros, they are converted into euros at the rate in force at the beginning of the day of the economic transaction.
Taking into account the requirements of the Accounting Law and practical circumstances, a source document must be written in Latvian. If a foreign person participates in the transaction, in addition to Latvian another language may be used. Contracts for the provision of services in the territory of Latvia must comply with the requirements of the Official Language Law.
Source documents are classified as:
If an economic transaction has both an external and an internal source document, the external document takes precedence.
The most commonly used are:
If a transaction involves goods, a goods delivery document is required to certify the fact of delivery and receipt and to ensure traceability of the movement of goods. It must contain the specified particulars (points 40 and 41). It is not mandatory to include information on the unit price and transaction value — in such a case an additional source document containing this information and a reference to the delivery document is required.
A signature is mandatory (the sender at the place of issue, the recipient at the place of receipt), except in the cases provided for in point 42 of Cabinet Regulation No. 877: if the document is prepared electronically and the parties certify/authorise it on the basis of an agreement on the delivery of goods (or sign it with a secure e-signature). Certification takes place in the processing system and the information must be available to both parties.
A goods delivery document may be omitted if payment is certified by a cash register receipt in accordance with legal acts, or if the movement takes place with international/domestic transport documents, or in certain cases for agricultural producers.
The source document and the goods delivery document may be combined in a single document. In that case, both the mandatory particulars of the source document and of the delivery note must be indicated.
A structured electronic invoice is prepared, sent and received in a structured electronic format that allows automatic processing and complies with the European e-invoicing standard (PEPPOL, etc.). A scanned PDF, JPG, etc. is not a structured invoice. In public procurement, the contracting institution (company) is obliged to accept structured e-invoices. It is planned that from 1 January 2028 in business-to-business transactions there will be an obligation to issue structured e-invoices.
In the double-entry system — as soon as possible, but no later than 20 days after the end of the month in which the source document was received or issued.
In the single-entry system—no later than 15 days after the end of the quarter in which the document was received or issued.
The procedure for corrections is laid down in the Accounting Organisation and Recording Regulations.
An erroneous entry in an accounting record is corrected by a new entry that corrects or cancels the previous one (for example, using a storno or reverse entry). The original entry must not be deleted or destroyed — the correction must be fully traceable.
A source document prepared in paper form may be corrected by making a correction on the document itself. In such a case, the correction must be explained (“Correction accepted”). It is also necessary to indicate who (given name, surname), when (date) and why (reason, justification) corrected the document. The correction must be signed by the person who corrected the respective document.
A document may also be corrected using an accounting certificate / statement (preparing a new document that can be attached to the document being corrected). Such an accounting certificate must indicate:
On the document being corrected, it must be noted that an accounting certificate has been prepared for the respective document and the date of the certificate must be indicated.