SAT electronic accounting in 2026 works best when it is managed as a monthly process, not as a file generated at the last minute. The quick answer is this: review chart of accounts, trial balance, XML files, acknowledgments and support before filing, so every period can be explained later.
Use this as an internal checklist if you are a legal entity, an administrative team, an external accountant or a business that needs clear evidence for each period.
Quick Answer
Prepare the chart of accounts if this is the first filing or if relevant changes were made, generate the trial balance for the period, validate balance continuity, compare against CFDI and bank records, create the files under the applicable schema, file through the SAT electronic accounting service and save XML, ZIP, acknowledgment and workpapers in a monthly folder.
It is not enough for the file to upload. The file must leave a record that explains how the trial balance was produced and who reviewed the differences.
If you came with a specific question, go directly to the section you need: chart changes, pre-XML checklist, acknowledgment review or monthly log.
Who Should Use This Guide
This guide is useful when:
- Your company files a monthly trial balance.
- You changed accounts or subaccounts and need to confirm the chart.
- You received a request where entries or ledgers may be needed.
- You are preparing a refund, offset or clarification.
- Management needs monthly compliance evidence.
- You handle multiple taxpayers and want to standardize folders and reviews.
If you use a simplified application or a regime with specific rules, validate your obligation first. This guide does not replace a review of regime, obligations or calendar.
Checklist Before XML
Before generating XML, review:
- Updated chart of accounts mapped to the applicable grouping code.
- Opening balances equal to the prior period closing balances.
- Monthly movements reconciled against bank records and journal entries.
- Issued, received, canceled CFDI and payment complements reviewed.
- VAT, withholdings and tax accounts reconciled against returns.
- New accounts documented with reason, date and owner.
- Files ready to be stored by period, not in generic folders.
Most problems do not start in the SAT portal. They start earlier: carried balances, duplicate accounts, canceled invoices still recorded or entries with weak support.
Go Deeper if You Detect This Pattern
| Pattern | What to review in depth |
| Balances change without explanation | Prior close, manual adjustments and reclassifications |
| New accounts mid-year | Chart, grouping code and documented reason |
| Canceled CFDI in the period | Entries, ledgers, substitutions and related returns |
| Scattered acknowledgments | Monthly fiscal folder with XML, ZIP and review evidence |
Operating Step by Step
- Define the exact period you will file.
- Close the month in the accounting system and block unauthorized changes.
- Reconcile bank records, CFDI and related returns.
- Review whether the chart remains current or document changes.
- Generate the trial balance and validate balance continuity.
- Prepare entries and ledgers if the case requires extra support.
- Generate XML and ZIP with the accounting system or authorized tool.
- File through the portal or Tax Mailbox, depending on the enabled flow.
- Download and save the acknowledgment.
- Record date, owner, result and observations in an internal log.
The order matters. If you generate XML before reconciling, you will probably correct the file instead of correcting the accounting cause.
How to Read the Acknowledgment
Review the acknowledgment the same day you file. Confirm:
- Taxpayer RFC.
- Type of file sent.
- Period and fiscal year.
- Folio or procedure identifier.
- Date and time.
- Filing status.
- Acceptance, rejection or observation message.
If the acknowledgment shows rejection or inconsistencies, do not resubmit blindly. Identify whether the issue is structure, period, chart, signature, duplicate file or accounting information. Save the rejection acknowledgment too because it explains the correction trail.
Frequent Errors
| Problem | Warning sign | Recommended correction |
| Chart not updated | New accounts do not appear or lack grouping code | Update chart and document reason |
| No trial balance continuity | Opening balances do not match prior close | Reconcile previous period before filing |
| Canceled invoices still recorded | Canceled CFDI remains in income or expenses | Adjust entry and keep evidence |
| Lost acknowledgment | No one can prove what was sent | Create monthly folder with acknowledgment, XML and ZIP |
| No review owner | Filing depends on one person | Assign owner and second review |
Minimum Monthly Log
A monthly log does not have to be complex. It should answer:
- Which period was filed.
- Which files were generated.
- Who reviewed the trial balance.
- Which differences were corrected.
- Where the acknowledgment is stored.
- If there was a rejection, what caused it and how it was fixed.
That record helps when the accountant changes, a new administrator joins or a review arrives. It also avoids relying on memory or scattered messages.
How Fintax Can Help
Fintax can help standardize the electronic accounting close: monthly review, chart validation, trial balance continuity, CFDI and bank reconciliation, acknowledgment folder and evidence file for each period.