INFONAVIT Instruction Letter and Withholding Notice

When you move forward with an INFONAVIT loan, you run into documents with unfamiliar names that can raise questions: the instruction letter (carta de instrucción) and the withholding notice (aviso de retención). Although they sound technical, they are key pieces that determine how the funds are disbursed and how your monthly payments are collected. In this guide we explain, clearly and without unnecessary jargon, what these documents are, when they are issued, who requests them, and at what point in the process they appear, all the way up to the signing of your deed (escritura).

What is the instruction letter?

The instruction letter is, in simple terms, the document through which the Institute tells the notary public (notario público) how the transaction must be formalized and how the loan amount must be disbursed. It works like a roadmap: it sets out the conditions under which the financing is granted, in whose name the loan is held, and the obligations that must be registered together with the purchase and sale.

This document is usually issued once you already have your loan approval and the property has passed the corresponding validations. The notary uses it as the basis for drafting the deed, making sure that everything the Institute requires is legally reflected. Without this set of instructions, the notary would have no certainty about how to set up the mortgage guarantee or how the loan must be recorded.

What is the withholding notice?

The withholding notice (also known as the notice of payroll deduction) is the document that informs your employer that it must deduct the monthly payment for your INFONAVIT loan from your paycheck and remit it to the Institute. In other words, it is the mechanism that triggers collection of your loan directly through salary deductions.

Thanks to this notice, your employer knows how much to withhold and from what date. It is generally generated once the loan has been formalized, and it provides certainty to both the employee and the employer that payment will be made. If you change jobs, your new employer must receive the corresponding notification so that withholding continues without interruption.

Who requests them and what they are for

In practice, it is the notary public (notario público) who handles and requests these documents as part of the formalization. The notary requests them from the Institute (or receives them through the platforms and processes INFONAVIT has set up) in order to put together the entire file before the signing. As the buyer, you normally do not process these papers on your own: they are coordinated among the Institute, the notary's office and, where applicable, the advisor accompanying you.

Each document serves a different but complementary function:

• Instruction letter: sets out how the loan is formalized and disbursed before the notary.
• Withholding notice: activates the deduction of your monthly payments through payroll with your employer.
• Both together: give legal and financial certainty to the transaction, from the granting of the loan to its collection.

To better understand the role of the notary and of the final document for your property, we recommend reading our guide on what a public deed (escritura pública) is.

The INFONAVIT appraisal in the process

Before these documents come into play, there is an essential step: the appraisal (avalúo). The INFONAVIT appraisal is a technical valuation carried out by an authorized appraiser or valuation unit to determine the value of the home you want to buy. It serves to confirm that the purchase price is consistent with the property's real value and that the property meets the minimum required conditions.

The appraisal result directly affects the transaction: if the appraised value is lower than the agreed price, you may have to cover the difference out of your own funds. That is why it's wise to have an idea of the property's value before moving forward. You can use our tool to calculate the value of a home as a rough reference.

Order and timing of the process up to the signing

Although every case is different, the general sequence of the process is usually organized as follows. Timing depends on how quickly you gather documents, the notary's availability and the validation of the property, so the figures you'll see are approximate and may vary.

1. You obtain your pre-qualification and your Loan Certificate (Constancia de crédito).
2. You choose the home and confirm that it is eligible for financing.
3. The appraisal is requested from an authorized appraiser or valuation unit.
4. The Institute issues the instruction letter for the notary.
5. The notary assembles the file and prepares the deed.
6. You sign the deed and the purchase and sale is formalized.
7. The withholding notice is generated so that your employer begins the deductions.

Keep in mind that these documents are part of a broader process. If you are just starting to explore housing options for your loan, you can begin your search in our catalog and compare properties in the area you're interested in.

Frequently asked questions

Do I process the instruction letter myself?

Generally, no. The notary handles it and receives it from the Institute as part of the formalization. Your role is to provide the documents requested of you and keep an eye on the progress of the process.

When is the withholding notice issued?

It is usually generated once the loan has been formalized, so that your employer begins deducting the monthly payment from your paycheck. The exact timing may vary depending on the case and the information the Institute has on record.

What happens to the withholding if I change jobs?

Your new employer must receive the notification in order to continue the deduction. If there is a period without contributions, check with the Institute on how your payments resume, since the debt is not canceled just because deductions stopped.

Does the appraisal have a cost and a validity period?

Yes, the appraisal generally has a cost and a limited validity period. Confirm the applicable terms with your appraiser or valuation unit, since they may be updated and depend on each transaction.