ABNT Citation Guide: How to Format References in NBR 6023:2025

ABNT (Associação Brasileira de Normas Técnicas) is the Brazilian standards organization that defines citation and formatting rules for academic work. NBR 6023:2025 is the current standard for bibliographic references, and it is required by virtually every Brazilian university for TCCs, dissertations, theses, and scientific articles.

If you are writing academic work in Brazil, ABNT formatting is not optional — it is a graduation requirement. Getting it wrong can mean your paper is returned for corrections, delaying your submission. The rules cover everything from author name formatting to punctuation placement.

Every ABNT reference follows a consistent structure: AUTHOR. Title. Publication details. The specifics vary by source type, but the general pattern is always the same. Author names are written in uppercase (last name first), titles use sentence case with bold formatting, and the reference ends with a period.

SILVA, José Maria. Metodologia da pesquisa científica. 3. ed. São Paulo: Editora Atlas, 2024.

SANTOS, Ana B.; OLIVEIRA, Carlos D. Inteligência artificial na educação superior. Revista Brasileira de Educação, v. 29, n. 1, p. 45-62, 2024. DOI: 10.1590/S1413-24782024000001.

BRASIL. Ministério da Educação. Diretrizes curriculares nacionais. Brasília: MEC, 2024. Disponível em: https://www.gov.br/mec. Acesso em: 12 mar. 2025.

ABNT has specific rules for each type of source. Here are the most common ones students need:

• Books — LAST NAME, First Name. Title in bold. Edition. City: Publisher, Year.
• Journal articles — LAST NAME, First Name. Article title. Journal Name in bold, v. volume, n. issue, p. pages, year. DOI.
• Websites — AUTHOR or ORGANIZATION. Page title. Site name, year. Available at: URL. Accessed: day month. year.
• Theses/dissertations — LAST NAME, First Name. Title in bold. Year. Type (Degree) — Institution, City, Year.
• Laws and legislation — JURISDICTION. Law number, date. Description. Source, location, date.
• News articles — LAST NAME, First Name. Article title. Newspaper Name in bold, city, day month. year. Section, p. pages.

ABNT uses the author-date system for in-text citations. There are two formats: parenthetical and narrative. In parenthetical citations, the author's last name appears in uppercase inside parentheses. In narrative citations, the name is part of the sentence and only the year is in parentheses.

A pesquisa demonstrou resultados significativos (SILVA, 2024).

Segundo Silva (2024), a pesquisa demonstrou resultados significativos.

"A inteligência artificial transformou a educação" (SANTOS; OLIVEIRA, 2024, p. 48).

After formatting thousands of ABNT references, these are the most frequent errors we see:

• Using lowercase for author names in parenthetical citations — it should be SILVA, not Silva, inside parentheses
• Forgetting the access date for online sources — every URL reference needs "Acesso em: day month. year"
• Abbreviating months incorrectly — ABNT uses abbreviated months with a period (jan., fev., mar., abr., maio, jun., jul., ago., set., out., nov., dez.)
• Missing the DOI when available — if a journal article has a DOI, include it
• Using "et al." too early — ABNT only allows "et al." when there are four or more authors
• Incorrect punctuation after titles — titles end with a period, then the subtitle follows without a new period

ABNT is unique compared to international citation styles. Unlike APA which uses Title Case for titles, ABNT uses sentence case. Unlike MLA which omits access dates for stable URLs, ABNT always requires them. And unlike Vancouver which uses numbered references, ABNT uses the author-date system similar to APA and Harvard.

If you are a Brazilian student, you almost certainly need ABNT. If your institution accepts international styles, check with your advisor before switching — most Brazilian universities require ABNT for official submissions like TCCs and dissertations.