Short answer
DENUE lists 81 coating and plating plants with 11 or more staff in Aguascalientes, Guanajuato, Querétaro and San Luis Potosí. 40 have 51 or more staff, and 10 of those match an IMMEX program on exact name and postal code. Querétaro has the most, with 28. Each plant still needs its own checks.
Key facts
- Activity codes (SCIAN)
- 332810
- Plants, 11+ staff
- 81
- Data
- INEGI DENUE bulk files, 25 Sep 2026; IMMEX directory, August 2026 edition
About coating and plating
Coating and plating plants finish metal parts: plating, e-coat, powder and paint. Environmental permits matter as much as process capability.
The numbers by state
| State | Plants, 11+ staff | With 51+ staff | With an IMMEX match |
|---|---|---|---|
| Querétaro | 28 | 13 | 3 |
| Guanajuato | 23 | 14 | 5 |
| San Luis Potosí | 17 | 9 | 2 |
| Aguascalientes | 13 | 4 | 1 |
| Four states | 81 | 40 | 11 |
| Staff band | Plants |
|---|---|
| 11 to 30 | 32 |
| 31 to 50 | 9 |
| 51 to 100 | 15 |
| 101 to 250 | 21 |
| 251 or more | 4 |
What to ask a coating and plating supplier
Registries show that a plant exists and exports. These questions cover what they cannot.
- Processes offered: zinc, zinc-nickel, e-coat, powder, anodize.
- Corrosion testing, such as salt-spray hours, and the records kept.
- Environmental permits and effluent treatment on site.
- Rack and barrel capacity against your part size and volume.
- Whether a certification body has audited the process to the customer’s specification.
Checks before you approach a plant
- Confirm the plant in DENUEName, address, activity code and staff band.
- Check its IMMEX programStatus and type, matched on legal name and postal code.
- Search the SAT 69-B listBy RFC where you have it, otherwise by exact name.
The verification guide explains each step and where it stops.
Frequently asked questions
How many coating and plating plants are in the Bajío?
INEGI’s DENUE lists 81 coating and plating plants with 11 or more staff across Aguascalientes, Guanajuato, Querétaro and San Luis Potosí. 40 of them have 51 or more staff. Testigo counted these from INEGI’s bulk files on 25 September 2026.
Which Bajío state has the most coating and plating plants?
Among the four states Testigo counted, Querétaro has the most coating and plating plants in DENUE, with 28 of 81, followed by Guanajuato (23). Plants elsewhere in Mexico are outside Testigo’s pilot, and counts are establishments in INEGI’s directory as of 25 September 2026.
Do coating and plating plants in the Bajío export under IMMEX?
Some do. 11 of the 81 plants match an IMMEX program on exact name and postal code, and 10 of the 40 with 51 or more staff. A plant with no match may still export through a shelter company’s program, so ask which entity holds it.