Searching for SAT tax advisory usually starts with a concrete question: an invoice is missing, the portal shows a difference, a return does not reconcile or someone received a notice. Some questions can be handled with official resources and careful review. Others need tax criteria because a wrong answer can affect returns, deductions, payments or future clarifications.
Official Sources to Review First
| Initial question | Useful resource | What it confirms |
| Invoice or CFDI | SAT verifier and invoice requirements | Whether the receipt exists and which fields are mandatory |
| Monthly return | Declarations and payments service | Period, obligation and general filing flow |
| Notice | Tax Mailbox | Formal channel, contact and communication evidence |
| Refund | SAT request and follow-up service | Procedure status and visible requirements |
Questions You Can Usually Organize Yourself
- Locate an official procedure and review basic requirements.
- Download acknowledgments, certificates or CFDI from the portal.
- Confirm general filing dates.
- Check whether an invoice is active.
- Gather documents before speaking with your accountant.
When Improvising Is Risky
| Situation | Why it needs review |
| Difference between CFDI and bank records | It can affect income, VAT or deductions |
| Requirement or invitation letter | The answer needs support and tax criteria |
| Relevant credit balance | The origin should be proven before requesting a refund |
| Regime change | It affects obligations, invoicing and future payments |
| Unusual transaction | It may require contracts, materiality or specific treatment |
Fast answers can be dangerous. The answer that works for one taxpayer may be wrong for another. In tax matters, context controls the result: regime, activity, period, documents and real operations.
How to Prepare a Useful Consultation
- Describe the problem in one sentence: what happened, when and what decision is needed.
- Have RFC, regime, period and business activity ready.
- Gather support: XML, acknowledgments, bank statements, contracts or portal screenshots.
- Separate facts from assumptions.
- Ask for options and risks, not only for the fastest path.
What Should Remain After the Call
| Result | Why it matters |
| Conclusion or review path | Avoids a vague answer no one can execute |
| Missing documents | Clarifies what is needed before deciding or correcting |
| Main risks | Helps choose between speed, cost and documentary certainty |
| Next action | Turns advisory into a task: download, correct, respond or wait |
| Owner | Defines whether the taxpayer, accountant, admin team or advisor acts |
If after asking for help you only have a verbal recommendation with no support, the advisory was incomplete. At minimum, you should know what was decided, with which information, what is missing and what evidence to keep.
How Fintax Can Help
Fintax can review your tax question with full context: CFDI, returns, bank records, regime and documents. If the issue can be solved with a simple action, we make it clear; if it needs analysis, we build the file needed to decide well.