Full privacy notice

This notice is issued under Mexico's Federal Law on the Protection of Personal Data Held by Private Parties and its applicable regulations. This English version is provided for convenience; in case of any discrepancy, the Spanish version prevails.

1. Who is responsible for your data

Gerardo Silva Vallejo, who operates under the trade name TANDEM Fiscal, with an address at Alcaldía Xochimilco, C.P. 16035, Mexico City, is responsible for processing the personal data you provide to us.

For any matter related to your personal data, write to us at gerardo.925@live.com or on WhatsApp at +52 55 1963 5289.

2. What personal data we process

Depending on the service you hire, we may process the following categories of data:

• Identification and contact: name, address, phone, email, CURP (population registry code) and official ID.
• Tax: RFC, tax regime, tax status certificate, tax returns, electronic invoices (CFDI), compliance opinion and notices from authorities.
• Financial and asset data: bank statements, income, expenses, assets, tax assessments and bank account details needed for payments or refunds.
• Corporate: articles of incorporation, shareholder minutes, powers of attorney and data on partners and representatives.
• Your employees' employment data (IMSS and payroll service): name, CURP, RFC, social security number, salary and registration changes.
• Access credentials: SAT password, e.firma and invoicing certificates, only when you authorize us to carry out procedures on your behalf.

Sensitive data. We do not request sensitive data. If a service requires it (for example, employee sick-leave certificates for the IMSS), we will process it only for that purpose and with your express written consent.

Third-party data. If you give us data about other people (employees, partners, relatives or suppliers), you confirm that you have informed them of this notice and have their authorization where the law requires it.

3. Why we use your data

Purposes necessary for the service:

• Providing the services you hire: accounting, tax returns, SAT procedures, IMSS and payroll, tax diagnosis (Tax Check-up), tax defense and corporate matters.
• Representing you or acting on your behalf before the SAT, the IMSS, Infonavit, local authorities and courts, when you authorize it.
• Preparing quotes, formalizing the service relationship, invoicing and collecting payment.
• Following up on your requests and keeping your file.
• Meeting our own legal obligations and responding to requests from authorities.

Additional purposes (not necessary for the service):

• Sending you tax deadline reminders and notices about changes in the law.
• Sending you information about our services and promotions.
• Asking for your feedback on the quality of our service.

If you do not want us to use your data for the additional purposes, let us know at any time by email at gerardo.925@live.com or on WhatsApp. Opting out does not affect the services you hire.

4. Passwords, e.firma and invoicing certificates

If you entrust us with your SAT password, e.firma or invoicing certificates, we store them encrypted, with restricted access, and use them only for the procedures you authorize. When the service ends we return them to you or delete them from our systems, as you instruct. We recommend changing your SAT password when the service ends.

5. Who we share your data with

We may transfer your data without requiring your consent, when necessary to provide the service or required by law, to:

• Tax, social security, labor and administrative authorities: SAT, IMSS, Infonavit, the Ministry of Labor (REPSE), treasuries and local authorities.
• Courts and the Taxpayer Ombudsman (PRODECON), in defense matters.
• Notaries and commercial notaries (corredores públicos), in corporate and real estate matters.

Our service providers (email, cloud storage, accounting and invoicing systems) and professionals who work with us on your matter may also access your data; they are bound to confidentiality and may use it only for that purpose. We do not sell, rent or share your data for commercial purposes.

6. How long we keep your data

We keep your data for as long as the service relationship lasts and, afterwards, for the periods required by tax and commercial law (generally five years for tax records) or while a matter is pending. Once those periods end, we block and securely delete it.

7. How we protect your data

We apply administrative, technical and physical security measures: access restricted to the staff handling your matter, encrypted storage of credentials and sensitive files, backups and confidentiality commitments. If a breach significantly affects your rights, we will inform you without delay.

8. Your ARCO rights and withdrawal of consent

You have the right to access your data, rectify it if it is inaccurate, cancel it when it is no longer needed and object to its use for specific purposes (ARCO rights). You may also withdraw your consent and limit the use or disclosure of your data.

Send your request to gerardo.925@live.com including:

• Your name and a way to reply to you.
• A copy of your official ID or, if a representative is acting for you, the document proving their authority.
• A clear description of the data and the right you wish to exercise.
• Any document that helps us locate your data.

We will reply within 20 business days at most. If your request is granted, we will carry it out within the following 15 business days. Please note that we cannot always delete data immediately, for example when the law requires us to keep it.

If you believe your right to personal data protection has been violated, you may contact the Mexican authority responsible for personal data protection.

9. This website

This site does not use tracking or advertising cookies. Fonts are loaded from Google Fonts, which may log technical data about your connection, such as your IP address. The contact form does not store anything on the site: it prepares your message so that you send it by WhatsApp or email, and the data you send us is handled under this notice.

10. Changes to this notice

We may change this notice due to changes in the law, our services or our practices. Any change will be posted on this page with its update date.

Last updated: October 1, 2026.