What Is a CFDI de Nómina and What Is It For?
A CFDI de nómina is the digital tax receipt a Mexican employer must issue every time it pays wages, salaries, or any income treated as salary to a worker. It isn't a regular invoice: it carries the complemento de nómina attached, an additional data block that details earnings, deductions, days worked, and everything else the SAT (Mexico's tax authority) needs to cross-check the employer's records against the employee's.
For the worker, this payroll receipt is their proof of income and the basis for their annual tax return. For the employer, it's the proof that the payroll deduction is valid for tax purposes: without the correct complement, the SAT can disallow the expense deduction on income tax.
The Complemento de Nómina 1.2: What It Is and What Fields It Includes
The complemento de nómina 1.2 is the current technical structure the SAT requires attached to every payroll-type CFDI. It replaced version 1.1 and has gone through several revisions since then that adjust catalogs, validations, and limits on certain concepts, without changing its overall logic.
Among the required fields the complemento de nómina 1.2 must carry:
- Issuer data: the employer registration number with IMSS (Mexico's social security institute) and the employer's RFC (tax ID).
- Recipient data: the worker's RFC, CURP, social security number, tax postal code, tax regime (605 for employees), and contract type.
- Employment data: work schedule, pay frequency, seniority, and the start date of the employment relationship.
- Earnings (percepciones), each identified with its SAT catalog key.
- Deductions (deducciones), also identified with a key, including withheld income tax and IMSS contributions.
- Payment date, which must match the day the worker actually received the money, not the day the receipt is stamped.
A CFDI de nómina missing any of these fields, or with data that doesn't match the SAT's or IMSS's own records, gets rejected before it can even be stamped.
Earnings and Deductions in the Complemento de Nómina 1.2
Earnings (percepciones) are what the worker receives: base salary, overtime, vacation premium, the year-end bonus (aguinaldo), commissions, and any other concept with its own key in the SAT catalog. Deductions (deducciones) are what gets subtracted: withheld income tax (key 002), the worker's share of IMSS contributions (key 001), court-ordered alimony, or any other authorized deduction.
One of the strictest validations in the complemento de nómina 1.2 is that every earning and every deduction must carry an amount, whether taxable or exempt; a concept can't be declared with no amount attached. On top of that, the taxable and exempt portions of each earning must add up to the total reported on the CFDI, and the withheld income tax must line up with the taxable income for the period. When any of those totals don't match, the PAC (the authorized certification provider) rejects the stamping before it ever issues a UUID.
That level of detail is exactly why running payroll off a spreadsheet gets risky as headcount grows: one capture error on a single earnings line can send dozens of receipts out with inconsistencies on the same payday.
Deadline to Stamp Payroll: What the SAT Requires
Unlike the complemento de pago, which has a grace period, the CFDI de nómina doesn't get as much flexibility. Mexico's Miscellaneous Tax Resolution allows the receipt to be issued before the payment date or within the following business days, with a window that varies by the employer's number of workers — generally somewhere between 3 and 11 business days after payment, depending on payroll size.
This matters because the SAT uses the CFDI de nómina's issue date — not the date the accountant finally uploads the file to the system — to validate that the income tax withholdings reported in the monthly provisional payment match the receipts actually stamped. Stamping late, or with the wrong date, creates a mismatch between what was declared and what was documented, and that's exactly what shows up in a SAT review.
The Most Common Errors That Get a CFDI de Nómina Rejected
Payroll stamping rejections almost always come down to the same handful of causes:
- A worker's RFC or CURP with one digit off. Since CFDI 4.0, the recipient's RFC gets validated against the SAT's own records, so a single wrong character kills the whole stamping attempt.
- Stamping with the wrong certificate, for example running one company's payroll under the digital seal (CSD) of a different entity in the same group.
- Earnings or deductions with no amount, or where taxable plus exempt doesn't add up to the declared total.
- The wrong payment date, entering the day the file gets uploaded instead of the actual day the salary was deposited.
- Stamping the year-end bonus or a special bonus as if it were regular payroll, without correctly splitting the taxable and exempt portions, which throws off the period's withheld income tax calculation.
- Using an outdated version of the complement, common in payroll systems that haven't migrated to the current schema.
Every one of these errors has the same result: the PAC won't stamp it, the receipt doesn't legally exist yet, and the employer has to fix and resubmit before the legal deadline runs out.
How to Avoid Rejections: Good Practices Before Stamping
The most reliable way to cut down rejections is validating a worker's RFC, CURP, and social security number against the official records before the first payroll run, not only at the moment they're hired. It also helps to keep your system's catalog of earnings and deductions current, make sure each special payment type (year-end bonus, profit sharing, severance) uses the right receipt type, and stamp payroll the same day it's paid instead of batching several periods together to upload at once.
These habits are well documented around the complemento de pago for regular invoices, but with payroll the discipline matters even more because the window to correct mistakes is shorter. Understanding first what a CFDI is and how it ties to the recipient's RFC — a topic we cover in our guide to what the RFC is — helps explain why these validations are so strict for payroll specifically.
How Businesses Automate Payroll Stamping
Stamping payroll by hand, checking receipt by receipt on a government portal, works fine with ten employees. With a hundred or more, every pay period turns into a race against the SAT's deadline, and a single capture error can hold up salary deposits for the entire workforce.
A well-integrated payroll system calculates earnings and deductions directly from the period's attendance and incidents, validates RFC and CURP against official records before generating the CFDI, builds the complemento de nómina 1.2 without manual entry, and sends the receipt to the PAC for automatic stamping. That doesn't just cut down on rejections — it also leaves a clean, ordered history for every receipt, useful both for a SAT audit and for a worker's own records.
Frequently Asked Questions
What is the complemento de nómina 1.2?
It's the technical data block the SAT requires attached to every CFDI de nómina, carrying the worker's tax and employment details: earnings, deductions, contract data, and employer registration data. It has been mandatory since it replaced version 1.1 and has gone through several revisions since.
How much time do I have to stamp payroll?
It depends on the employer's number of workers: the Miscellaneous Tax Resolution allows stamping before payment or within a range of business days afterward, without the extra grace period that applies to the complemento de pago. Confirm the exact window for your headcount with your accountant or your PAC.
What happens if my CFDI de nómina gets rejected by the SAT?
The PAC doesn't issue a UUID and the receipt doesn't legally exist until the error is fixed and it's stamped again. The employer stays within the legal deadline only if the fix happens before that deadline runs out, which is why it's better to stamp as soon as payroll is processed rather than waiting until the last day of the window.
Is the year-end bonus stamped the same way as regular payroll?
No. The year-end bonus (aguinaldo) and other extraordinary payments like profit sharing (PTU) need to be stamped with the correct earnings type, carefully splitting the taxable portion from the exempt one, because mixing them into regular payroll throws off the period's withheld income tax calculation.
Do I need a PAC to stamp payroll?
Yes. Just like any other CFDI, the complemento de nómina has to be stamped through a Proveedor Autorizado de Certificación (PAC) validated by the SAT; without that stamping, the receipt has no legal tax standing.
If your business is still building payroll by hand or losing hours fixing rejections every pay period, at AISDC we connect CFDI invoicing with payroll software that calculates earnings and deductions, validates worker data, and stamps the 1.2 complement without manual entry.