Unfiled Payroll Variables and an Open Union Issue: How We Sorted Out a 250-Employee Transportation Payroll

A ground transportation operation with 250 employees came to ADN with two problems at the same time. There were unresolved union issues, and the previous provider hadn't filed payroll variables.

The company has been with ADN for seven years. Both issues got closed.

Why unfiled variables is the more serious problem of the two

Of the two, the union issue makes more noise. The other one costs more money.

In transportation payroll, a large part of what an operator earns isn't base salary. It's overtime, Sunday premium, seventh-day pay, mileage or per-trip bonuses, and compensation that changes every period. Those are the variables.

Those earnings aren't just extras you pay and move on. They integrate into the salary base for contribution purposes (salario base de cotización), the figure used to calculate contributions to Mexico's Social Security Institute (IMSS) and to INFONAVIT (the national housing fund). Mexican law requires reviewing and filing that integration every two months.

When a provider doesn't file the variables, three things happen at once, and none of them show up in the month's financial statement:

1. The company contributes below what it owes. The difference doesn't disappear, it accumulates as a liability with adjustments and penalties until the authority determines it.
2. Employees get shortchanged without knowing it. Their contribution record is worth less than it should be, which affects their pension and their INFONAVIT credit capacity.
3. The company is exposed exactly where a union looks first.

That third point connects the two problems on this account. An operation with poorly integrated variables and an active union doesn't have two separate problems. It has one problem, on two fronts.

What we did

The backlog went back two years of unfiled variables when ADN took over the account. It was caught immediately, in the initial review. By the time the IMSS requirement arrived, most of the correction work was already done: the pending variables were filed, the salary base integration was corrected, and the difference was self-reported to IMSS before the authority imposed it.

Self-reporting isn't the same as waiting for a fine. It changes the amount, and it changes the conversation with the authority: arriving with the work already done is different from getting caught.

The union issue was resolved in parallel, with ADN's labor attorney. It's an operation with a strong union presence, and that front doesn't get solved with payroll. It gets solved with negotiation and the right legal framework behind it.

What we can say with what's documented: in seven years, the operation hasn't had another open issue over variable integration.

What we learned from this account

When a company switches payroll providers, the conversation is almost always about the future: how calculations will run, how often reports come out. This account left us with the opposite habit.

Now, on any operation with heavy variables, the first thing we check when we take over isn't how next period will look. It's what was filed, and what wasn't, in the periods that already passed. Inherited liability doesn't announce itself. It shows up when the requirement arrives, already carrying adjustments and penalties.

It's a review that makes people uncomfortable, because it sometimes finds things nobody wanted to find. It's worth it anyway.

If your operation has heavy variables

Three questions you can answer without anyone's help, today:

• Do you know the last time the salary base for contributions was updated for your operators?
• Are overtime, Sunday premium, and per-trip bonuses integrated into that figure, or do they only show up on the pay stub?
• If an IMSS requirement showed up tomorrow for the last five years, do you have the supporting paperwork for every period?

If you hesitated on any of these, it's worth checking. With us or with whoever runs your payroll.

This is a real case. Identifying details are withheld under a confidentiality agreement with the client. Headcount and tenure figures were provided by the company. The regulatory information on this page is general in nature and doesn't constitute legal or tax advice; IMSS, INFONAVIT, SAT, and STPS regulations are updated periodically.