The construction logbook in Mexico: what the law requires and how to keep it error-free
Last reviewed: Regulations change: the text is checked against the official source at each review.
The bitácora de obra is the technical instrument that serves as the formal channel of communication between the parties to a public works contract, where the important matters and events of the start, execution and conclusion of the works are recorded. On federal public works it is mandatory and kept by electronic means.
Note: this article describes the general framework in force at the time of publication. The LOPSRM was amended on April 16 and November 14, 2025, and Mexico’s federal procurement ecosystem is still in transition. Always verify the current text and the administrative provisions applicable to your contract before making decisions.
Its legal basis is the Public Works and Related Services Law (LOPSRM). Article 52 Bis establishes that the logbook is mandatory in works and services contracts and that it shall be kept by electronic means, while Article 52 Ter allows the Ministry to authorize conventional means in exceptional cases, such as technological difficulties or security risks.
Conventional and electronic
The conventional logbook is a physical book, folio-numbered, in an original and two copies, which must remain at the site office for the parties to consult. The electronic one is a digital system that requires an advanced electronic signature for every note and offers real-time information, authenticity and digital backup.
In practice, the electronic logbook is the rule and the conventional one the authorized exception.
What BESOP is
Since 2018, the Electronic Logbook and Public Works Tracking System (BESOP) has been in operation — the technical instrument that serves as the channel of communication between the parties to works contracts, where the important matters and events of the start, execution and conclusion of the works are recorded. It replaced the earlier Electronic Public Works Logbook, and logbooks opened in the previous system are kept there until closed.
It is administered by the Anticorruption and Good Government Ministry, and it uses the advanced electronic signature to give certainty to each note. In various guides and state agencies it also appears as BEOP, which breeds confusion: if someone on your project mentions one or the other, confirm which system they mean.
A point that matters for scope: BESOP applies to contracts charged to federal funds. The states have their own public works laws and their own systems or requirements. Before assuming BESOP applies, verify the source of your contract’s funds.
What changed with the 2025 reforms
The reforms of April 16 and November 14, 2025 did not repeal the logbook’s mandatory status or the BESOP system, but they created a new Digital Public Procurement Platform, Compras.mx, replacing CompraNet; strengthened end-to-end digitization of the process with electronic signatures throughout; and reassigned powers to the new Anticorruption and Good Government Ministry.
For whoever runs the works, the practical reading is this: the obligation did not change, but the administrative environment did — and references to the Ministry of Public Administration or to CompraNet in internal documents and procedures are now out of date.
Who signs
Notes must be signed by those with authority to do so — typically the resident engineer on the agency’s side and the construction superintendent on the contractor’s side, plus the external supervision where there is one.
Access to BESOP is granted to specific individuals, and the advanced electronic signature binds each note to its author in a way that cannot be repudiated. This has a practical consequence worth understanding well: a note signed with your electronic signature is yours, no argument. Sharing credentials is not an administrative shortcut — it is assuming authorship of everything recorded with them.
What a note must contain
Each note must let a third party understand what happened without further explanation:
- Sequential number and date
- Classification of the matter
- Objective description of the fact or the instruction
- Precise location where applicable
- Reference to documents: drawings with their revision, letters, standards
- A concrete request when the note requires an answer
- The signature of whoever records it
The mistakes that strip a note of its value
Backdating by delay. Recording today what happened a week ago. It weakens the note and in some cases constitutes an irregularity.
Vague description. “Problems arose on the north front” substantiates nothing. The note has to be verifiable by someone who was not there.
Emotional loading. An entry full of reproaches reads as a partial account. Neutral description is more credible and more effective.
Not requesting an answer when one is needed. If the note requires a decision from the client, it has to say so explicitly and preferably state the deadline. An informative note creates no obligation to respond.
Recording only your own side. The costliest mistake. Resident engineers tend to record their own progress diligently and omit what the counterparty failed to do. Later there is no way to substantiate a time extension.
Sharing credentials. Said already, and worth repeating: the advanced electronic signature identifies you beyond dispute.
Private projects
None of the above applies by law to private construction. There, the logbook exists because the contract establishes it, and the parties define its format.
That is freedom, and it is also risk: if the contract says nothing, nobody keeps a logbook, and when a dispute appears neither party has anything to stand on. The sound practice is to include, in the private works contract, a clause designating the instrument, its format, who is authorized to record, the response period and the acknowledgment mechanism.
Frequently asked questions
- Is the bitácora mandatory on private projects?
- Under federal public works law, no. Requirements may arise from local building regulations or from the responsible site director's certification. Contractually, it depends on what the contract establishes.
- Can I use a paper logbook on a federal contract?
- Only with authorization, and in the exceptional cases the rules provide for, such as lack of connectivity or security conditions. It is not the contractor's call.
- What happens if no logbook is kept?
- On public works it can lead to administrative liability for the public servants involved and to findings from oversight bodies. For the contractor the practical effect is worse: without a logbook there is no way to substantiate time extensions, extra work or claims.
- Can the supervision refuse to answer a note?
- They can fail to answer, and that silence is itself a recordable fact. Put the lack of response on record with a follow-up note. A documented absence of reply is often as useful as an unfavorable one.
- Do logbook notes replace formal letters?
- Not necessarily. Many contracts require formal written notice for certain acts. The logbook and formal correspondence complement each other; check your contract's notices clause to know what each act requires.
Founder and CEO of Paladio. He has spent more than 15 years building financial products that touch the lives of millions of people. He writes about what he sees on site: how progress is really measured and where the money leaks.
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