Short answer. Yes. Labor Code Article 278 states that this Title applies to all establishments or undertakings, whether for profit or not, with no exception written in for size or how formally the business is run. Being small or informal does not, on the wording of the article, take an employer outside its reach.
What the law says
Coverage. The provisions of this Title shall apply to all establishments or undertakings, whether for profit or not.
Labor Code, Article 278 — Who This Title Covers. Read the full provision →
The coverage rule does not carve out small operations
Article 278 is short and deliberately broad: the provisions of this Title shall apply to all establishments or undertakings, whether for profit or not. It does not say "registered establishments", "establishments above a certain size", or "formally organised undertakings". It says all of them. If your employer runs a shop, a stall, a small workshop or any other operation where you work for pay, that operation is an establishment or undertaking for this purpose, and the article does not ask how big it is or how formally it keeps its books before it applies.
"Whether for profit or not" widens it further
The article goes out of its way to add whether for profit or not, which rules out an argument that an informal, barely-profitable, or even non-profit operation sits outside the Title because it does not look like a conventional business. An enterprise being small, cash-based, or run without the paperwork of a larger company is not the same as it being outside this coverage rule. The text conditions coverage on there being an establishment or undertaking where you work, not on that operation's scale or formality.
What this article does not settle
Article 278 answers only whether this Title of the Labor Code applies to your employer at all — it is a coverage rule, not a list of what you are entitled to. It does not itself say whether particular benefits work differently for very small employers, and this text does not give grounds to claim any such carve-out exists for your situation. If someone tells you a specific entitlement does not apply because the business is small, that claim rests on a different, separate provision — not on Article 278, which draws no size line at all.
What to do if your coverage is being questioned
Do not accept "we're too small" or "we're not really a company" as a reason you fall outside the Labor Code's protections; Article 278's own wording does not support that line. Keep whatever shows the working relationship — pay slips, messages about your schedule, receipts for pay received, anything naming who you worked for and what you were paid. If a specific benefit is being denied and you are told an exemption applies, ask what provision it is based on, and bring that document, along with your own records, to a lawyer to check.