Invoicing Regulations and Billing Compliance Standards

Third-Party Billing Requirements

Invoices issued by third parties must fulfill the following requirements to be valid:

• A prior written agreement must exist.
• Each bill must be accepted by the entrepreneur or business operation within 15 days of receipt.
• Bills issued by third parties or for recipients must utilize a distinct standard numbering system for each party involved.

Deadlines for Invoice Issuance and Delivery

Non-Entrepreneur or Non-Professional Recipients

Delivery must be made at the time of the operation and shipment, coinciding with its issuance.

Entrepreneur or Professional Recipients

Invoices must be issued within one month from the conduct of the operation, or before the 16th day of the following month to complete the liquidation of operations. Shipping must occur within one month from the date of issuance.

Bill Summaries

Delivery should occur on the last day of the natural month in which operations were conducted. The term of shipment is at the time of issuance.

Bill Summaries for Entrepreneurs and Professionals

Delivery is required one month after the last day of the calendar month when operations were paid. If applicable, this must be done before the 16th of the month following the expiry of the liquidation period. Shipping must occur within one month of issuance.

Duplicates and Copies of Bills

Entrepreneurs and professionals may only issue one original of each invoice or replacement. Duplicates may be issued under the following conditions:

• If there is more than one target operation.
• In the event of the loss of the original.

Each duplicate must include the term "Duplicate" and the specific reason for its issuance. All copies of the bill must be clearly marked as a "Copy."

Storage of Invoices and Substitute Documents

Employers and professionals are required to conserve the following documents:

• Substitute bills and documents received.
• The parent or copies of bills issued and copies of substitute documents.
• Supporting documentation for the receipt of refunds under the special regime for agriculture, livestock, and fisheries.
• Documents regarding the payment of import tax.

Electronic Storage Requirements

If handled electronically, the issuer is obligated to hold the parent or copies of bills in their original format. Similarly, the recipient must keep the original bill in the format in which it was received. These bills must be retained to facilitate the payment of VAT.