TL;DR — Quick Summary

Fix Aspel COI trial balance errors for SAT: missing agrupador codes, wrong account nature, rounding issues, and SAT portal rejections explained step by step.

The trial balance (balanza de comprobación) is one of the three files that Mexican companies are required to submit monthly to the SAT as part of electronic accounting (contabilidad electrónica). When Aspel COI shows errors generating it — or when the SAT portal rejects the XML — the root cause is almost always in the chart of accounts: missing agrupador codes, incorrect account nature, or rounding discrepancies. This article covers the most common scenarios and how to fix them.

The Error

The most frequent error messages and symptoms when generating the trial balance in Aspel COI are:

  • “Error generating the trial balance” — a generic message that can indicate problems in the chart of accounts, journal entries, or the database.
  • Trial balance shows zero values even though journal entries exist for the period.
  • The XML fails XSD schema validation: the SAT validator reports empty fields or incorrect data types.
  • The SAT portal rejects the file with messages like “RFC does not match”, “Invalid submission type”, or “Trial balance does not match the submitted catalog”.
  • Rounding discrepancy: debit and credit totals in the XML differ by a few cents and the SAT will not accept the file.
  • Accounts with negative balances that should be positive, indicating that the account nature is inverted.

These errors occur most often at the start of a new fiscal year, when new accounts are added to the chart of accounts, or after updating Aspel COI to a new version.

Root Cause

Missing agrupador codes in the chart of accounts

The SAT requires every accounting account to be linked to a code from the minimum agrupador catalog (published in Annex 24 of the Resolución Miscelánea Fiscal). In Aspel COI, this code is entered in the SAT Agrupador field within the chart of accounts. If an account has no agrupador, its balances are simply excluded from the XML, leaving the trial balance incomplete or entirely blank.

Incorrect debit/credit nature

Each account must have the correct nature assigned:

  • Debit: assets (100), costs (400), expenses (500), debit memo accounts (800).
  • Credit: liabilities (200), equity (300), income (400 income group), credit memo accounts (900).

A liability account marked as debit will generate negative balances in the XML. The SAT schema does not allow negative balances for those account types and will reject the file.

Rounding discrepancies

Aspel COI works internally with up to six decimal places, but the trial balance XML only accepts two. If the export process does not round correctly, the sum of all balances may differ by $0.01 or $0.02, causing the XML to fail XSD validation.

Journal entries not posted to the general ledger

Entries that are captured but not posted to the general ledger do not appear in any report or in the trial balance XML. Posting is a manual step in Aspel COI that many users skip.

Chart of accounts sent to SAT does not match the trial balance

The SAT validates that all accounts in the trial balance exist in the catalog previously submitted. If you added accounts after the last catalog submission, you must resubmit the updated catalog before uploading the trial balance.

Step-by-Step Solution

Step 1: Verify and complete agrupador codes in the chart of accounts

  1. In Aspel COI, go to Catalogos > Plan de cuentas.
  2. Enable the SAT Agrupador column in the view (if hidden, go to View > Columns and add it).
  3. Sort by the Agrupador column to bring accounts without a code to the top.
  4. For each account without an agrupador: select it, click Modify, and assign the correct code from the SAT minimum catalog. Refer to Annex 24 of the current year’s Resolución Miscelánea Fiscal.
  5. Repeat until all accounts with movements have an agrupador assigned.

Parent (heading) accounts may not require a direct agrupador if all their sub-accounts have one assigned. However, assigning it to the parent as well avoids ambiguity.

Step 2: Fix account nature

  1. In Catalogos > Plan de cuentas, review the Nature column.
  2. Confirm that asset accounts (1xx) are Debit and liability and equity accounts (2xx, 3xx) are Credit.
  3. To correct: select the account, click Modify, change the Nature field, and save.
  4. If the account has a historical balance, the correction will affect the presentation of prior-period balances. Consider making the change at the start of the fiscal year.

Step 3: Post journal entries to the general ledger

  1. Go to Polizas > Afectar al mayor.
  2. Select All types of journal entries (general, income, expense, checks, etc.).
  3. Set the date range for the reporting period.
  4. Click OK and wait for the process to complete.

Step 4: Regenerate the trial balance

  1. Go to Reportes > Balanza de comprobacion.
  2. Select the Contabilidad electronica option (not the regular printed trial balance).
  3. Choose the submission type: N (normal, first submission), C (complementary), or X (correction).
  4. Select the period and click Generate XML.
  5. Save the XML file to an accessible folder.

Step 5: Validate the XML with the SAT validator

  1. Download the XML Validator from the SAT portal (search for “validador de contabilidad electrónica” on sat.gob.mx).
  2. Open the validator and load the trial balance XML file.
  3. Run the validation. The validator will display specific errors: empty fields, incorrect data types, or accounts not present in the previously submitted catalog.
  4. Fix the errors in Aspel COI and regenerate the XML until validation passes.

Step 6: Upload the trial balance to the SAT portal

  1. Log in to the SAT portal using your e.firma or password.
  2. Go to Contabilidad Electronica > Envio de informacion contable.
  3. Select the Trial balance file type and the corresponding month/year.
  4. Upload the XML file and submit.
  5. Download and save the acknowledgment receipt with the assigned folio. This receipt is your proof of compliance in the event of an audit.

Alternative Solution

Manual XML correction for rounding errors

If the SAT validator rejects the XML solely because of a $0.01 difference in totals, you can open the XML file in a text editor (Notepad++ or VS Code) and manually adjust the <SaldoFinal> value of the last account so that the totals balance exactly. Save the file and validate again.

This manual correction is only valid for single-cent rounding differences. If the discrepancy is larger, there is a real error in the journal entries that must be corrected from within Aspel COI.

Resubmitting the catalog before the trial balance

If the SAT portal rejects the trial balance because accounts do not match the registered catalog:

  1. Update and resubmit the chart of accounts from Aspel COI (Reportes > Catalogo de cuentas > XML).
  2. Wait for the SAT to process the new catalog (typically within minutes).
  3. Upload the trial balance again.

Prevention

To avoid monthly errors when generating the trial balance:

  • Assign the agrupador immediately when creating a new account. Do not leave accounts without agrupador codes; the error is not detected until you try to generate the trial balance.
  • Verify the account nature when creating it. A liability account marked as debit is hard to spot until negative balances appear in the XML.
  • Post journal entries the same day they are entered, or at least at the end of each week.
  • Submit the chart of accounts to the SAT every time you add a new account, before sending that month’s trial balance.
  • Always validate the XML locally with the SAT validator before uploading to the portal. The validator identifies errors in seconds; the SAT portal can be slow and often returns unclear error messages.
  • Save the acknowledgment receipt for every submission, organized by year and month. They are essential if the SAT initiates a review.

Summary

  • The most common cause of trial balance errors for the SAT is missing agrupador codes in the chart of accounts.
  • Incorrect account nature (debit/credit) generates negative balances in the XML that the SAT rejects.
  • Journal entries must be posted to the general ledger before generating the XML.
  • Rounding differences of $0.01 can be corrected manually in the XML; larger differences indicate a real accounting error.
  • Always validate the XML locally with the SAT validator before uploading to the portal.
  • The chart of accounts must be current in the SAT system before submitting the trial balance for the month.