Few documents shape the future of an industrial project as much, and are as poorly understood, as the CFE feasibility letter. It is the formal answer from CFE Distribution to a simple question: does your grid have enough power to give me the kVA I need? The answer is not a yes or a no: it is a technical document that sets how much you will pay to connect or grow, in how long, and under what conditions. Whoever reads it well negotiates the project better; whoever only looks for the word "approved" finds out too late that the reinforcement works cost more than the new machine.
This article takes the feasibility letter apart field by field: what each data point says, what you must verify before signing anything, and what red flag it hides. We don't reproduce an official format —the format varies by division and gets updated— we describe the fields you will actually find and flag what is typical of the procedure and what is regulated.
What is a CFE feasibility letter, and when do you need it?
The feasibility letter is the official document by which CFE Distribution rules whether the local power grid can serve the load you request and under what conditions. It is a prerequisite to installing a meter or signing a service contract. You need it when you open a new medium-voltage service, when you increase your contracted load, or when a project requires technical validation of the grid before investing.
In practice, almost any relevant industrial move triggers it: a new plant, an additional production line, a building expansion, or an increase in the contracted demand of an existing load center. If your area's grid has spare capacity, the letter can be resolved quickly and without works; if it is saturated, the same procedure becomes the point where the project's economic viability is decided.
Who issues it and why the right area matters
It is issued by CFE Distribution, not the CFE Basic Supply that bills your electricity. This distinction matters: feasibility is a ruling on the physical grid, independent of who you contract energy with. In fact, if your load takes you to the Wholesale Electricity Market (MEM), you will still need to resolve the physical connection with CFE Distribution or, depending on the voltage level, with CENACE, even if you buy your energy from a Qualified Supplier. Feasibility answers "does the load fit on the grid?"; the energy contract answers "who do I buy the kWh from?". They are two distinct decisions best not confused.
Anatomy of a CFE feasibility letter, field by field
The heart of this article is the table below. Each row is a field you usually find in the ruling, what it means, what you must verify, and the red flag it triggers. Use it as a checklist when you receive your letter.
| Letter field | What it says | What you must verify | Red flag |
|---|---|---|---|
| Folio and applicant data | Identifies the procedure, the property, and the person or company | That the RFC, address, and property match your project exactly | Any incorrect property data invalidates the rest |
| Requested load (kW / kVA) | The demand you asked to be evaluated | That it matches your real installed load plus planned growth, not today's | Under-loading today forces you to repeat the procedure when you grow |
| Ruling outcome | Approved, conditionally approved, or not approved without works | Which of the three outcomes it is and under what assumption | "Conditional" without reading the conditions is a trap |
| Connection point | The physical node where you connect, usually in UTM coordinates | The real distance from your property to that point | A distant point means meters of line at your cost |
| Voltage level | The assigned supply voltage | That it is consistent with your load, typically medium voltage 13.2, 23, or 34.5 kV | A higher voltage than expected makes the substation more expensive |
| Available grid capacity | How many free kVA there are in the transformer or circuit | Whether your load fits with margin or saturates the element | A tight margin pushes future works onto your account |
| Reinforcement works | Grid expansions needed to serve you | Scope, who executes them, and under what scheme | It is the line that inflates the budget the most |
| Budget or contributions | Estimated cost of works and contributions due from you | What portion is a regulated contribution and what is third-party works | A high cost here can sink the business case |
| Ruling validity | The deadline to execute works and contract | The deadline, typically around 12 months | A short validity pressures you to decide without analyzing |
| Special technical conditions | Requirements such as specific metering or Grid Code | What studies or equipment it requires before energizing | An ignored condition halts energization at the end |
Values such as the validity of around 12 months or the voltages of 13.2, 23, and 34.5 kV are typical of the procedure and of distribution practice; it pays to confirm them against the specific ruling you receive, because they vary by division and by the provisions in force.
The three possible outcomes, translated
Every letter lands on one of three outcomes. Approved without works: the grid has capacity, you connect paying only the regulated contributions. Conditionally approved: there is capacity, but subject to minor modifications or technical conditions you must meet before energizing. Not approved without reinforcement works: there is no capacity; CFE defines the necessary works and delivers a cost estimate to enable supply. The third outcome is the one that completely changes the project's economics, and it is almost always channeled through third-party works.
What are third-party works and why do they drive up cost?
When the grid lacks capacity, CFE does not always expand it with its own budget: it conditions service on you executing the reinforcement works. Under the third-party works scheme, your project builds the infrastructure —medium-voltage lines, a substation, reinforcements— with drawings and specifications approved by CFE, and then hands it over to be integrated into the public grid.
This matters because that line can cost more than the production equipment that prompted the expansion. A saturated industrial area can turn a "simple" load increase into a several-million-peso project and several months of execution. That is why the budget and the scope of works are the fields that deserve your coldest reading: that is where the business case is won or lost, not in the energy tariff.
How long does the feasibility letter take and how much does it cost?
The procedure usually unfolds in stages: a documentary review of a few business days, an on-site inspection where the zone transformer's capacity and the distance to your service drop are validated, and the issuance of the ruling. As a typical reference, the documentary review runs around 2 to 5 business days, the inspection 10 to 15 business days, and the full project up to connection can take 12 to 24 weeks when works are involved.
These timelines are indicative and depend on the division, the zone's workload, and whether your case requires works. The operational lesson is to plan with margin: feasibility is not a one-day counter procedure, and its outcome can add months of construction to the schedule. If your investment depends on a start date, feasibility is one of the first things you should launch, not the last.
What decisions does feasibility enable for your industry?
Read well, the letter is not just a permit: it is information to decide the site's energy direction. The available capacity and the cost of works tell you whether it pays to increase load while connected to the grid, whether it is a good moment to migrate to the MEM as a Qualified User, or whether the most profitable answer is to generate part of your energy on-site instead of asking a saturated grid for more kVA.
Load increase, migration to the MEM, or on-site generation
If the ruling shows ample capacity and reasonable contributions, a conventional load increase is the simple path. If your demand crosses the threshold of roughly 1 MW, feasibility becomes input for a bigger decision: migrating to the MEM. As a Qualified User you register with the CRE and sign a connection contract with CENACE, which lets you buy energy at market price through a Qualified Supplier instead of the regulated tariff. There it pays to understand in depth the difference between a Qualified Supplier and CFE Basic Supply, because feasibility resolves the physical connection but not who you buy the kWh from.
That second decision is the one that moves the bill. An electronics and entertainment operation in Jalisco that was paying a tariff comparable to CFE Basic Supply restructured its contracting scheme with a Qualified Supplier, tailoring it to its operational reality, and went on to save MX$29 million in 2024 (see the full success story).
And when the letter reveals expensive reinforcement works or insufficient capacity, on-site generation stops being a green idea and becomes a concrete economic alternative: producing part of the load locally can avoid grid reinforcement altogether. That calculation —distributed generation vs grid-connected central generation— is only done well with the letter's cost of works in hand.
How Enerlogix reads your feasibility letter
At Enerlogix we treat the feasibility letter as what it is: a decision document, not a procedure to file away. We read it field by field, translate the reinforcement works into their real impact on the business case, and cross-reference it with your load profile to decide the best path: increase load, migrate to the MEM, or generate on-site. As an independent consultancy, we don't charge a spread on your energy or sell you the works: our only product is the right recommendation for your project.
Request a free evaluation or learn about our energy purchasing service. We work with your real bill and your real ruling.
As an official reference, you can consult the CFE portal for service procedures and the Energy Regulatory Commission portal for Qualified User registration.
Frequently asked questions
No. The feasibility letter is a ruling from CFE Distribution on whether the physical grid can give you the load and under what conditions. The energy contract defines who you buy the kWh from, whether CFE Basic Supply or a Qualified Supplier in the MEM. They are two separate decisions: one resolves the physical connection and the other the energy purchase.
It depends on the division and whether your case requires works. As a typical reference, the documentary review runs around 2 to 5 business days, the on-site inspection 10 to 15 business days, and the full project up to connection can take 12 to 24 weeks when reinforcement works are involved. It pays to launch feasibility at the start of the project, not at the end.
The three most important ones are costly reinforcement works, insufficient or tight available capacity in the transformer or circuit, and a short validity that pressures you to decide quickly. A distant connection point is one too, because the meters of line to your property usually run on your account. Each one can completely change the project's economics.
It is typical for the ruling to state a validity of around 12 months to execute the works and contract the service, though it can vary by division and by the provisions in force. It pays to verify the exact deadline in your letter, because if it expires before closing the project you will have to repeat or update the procedure and the capacity assumptions may have changed.
Yes. Feasibility resolves the physical connection to the grid and is independent of who you buy energy from. Even if you migrate to the MEM and buy from a Qualified Supplier, you must resolve the connection with CFE Distribution or, depending on the voltage level, with CENACE. The letter tells you whether the grid supports your load; the MEM only changes who you buy the kWh from.
