Executive answer
Mexico’s Information on Tax Situation, known as ISSIF, is not a second transfer pricing study. It is information submitted with the annual income tax return by taxpayers within Article 32-H of the Federal Fiscal Code. Its schedules and questions expose related-party dealings, methods, adjustments, Article 76-A filing status and transactions with foreign residents. It therefore makes differences among the study, accounting records and returns visible.
For fiscal year 2025 information filed in 2026, Annex 16 of the 2026 Miscellaneous Tax Resolution was published in the Official Gazette on January 19, 2026. The formats include schedules for related-party transactions, taxpayer information about those dealings and foreign-resident transactions. The exact structure depends on taxpayer type and the applicable format guide.
Reliable preparation assigns every field to a source, owner and cross-check. The study supports method and arm’s length outcome. The ledger supports amounts. Anexo 9 and the local return provide reporting comparisons. Legal validates relationships and agreements. Accounting validates true-ups. Tax approves the final response.
Who files ISSIF
Article 32-H of the Federal Fiscal Code lists categories required to provide information on their tax situation as part of the annual return. The population includes categories based on revenue, companies within the optional group regime, government-related entities, foreign residents with a permanent establishment, transactions with foreign residents and other categories in the current text.
Applicability must be tested by taxpayer and year. One group company exceeding a threshold does not automatically make all entities filers. The appearance of a software section is not sufficient evidence. Prepare a sheet identifying the relevant statutory category, figures, dealings, regime and conclusion.
Some Article 76-A references use Article 32-H categories. That creates overlap, not equivalence. One entity may file ISSIF plus local, master or CbCR returns. Another may file ISSIF without all three. Keep separate obligation columns.
Transfer pricing information in the formats
Applicable formats may include a schedule of controlled dealings with amount, type, method, indicators, range, adjustments and tax information. Another schedule requests taxpayer statements on compliance, documentation, returns and positions. The foreign-resident module adds amounts, withholding, treaties and related-party status.
Annex 16 published for 2026 includes schedules titled “Transactions with related parties” and “Taxpayer information on its related-party transactions.” Depending on the format, questions can address unique and valuable contributions, arm’s length status, VAT effects of adjustments, treaty benefits and Article 76-A obligations.
Not every field applies to every taxpayer, but a “no” answer still needs support. The preparer requires access to agreements, studies, workpapers, returns and specialists and should not answer technical questions by intuition.
Begin with a traceability matrix
Identify the format guide for the taxpayer type and fiscal year. Export every transfer pricing index or field into a matrix. Record the identifier, question, data type, primary source, cross-check, preparer, reviewer and conclusion.
Group fields into five families: applicability and relationships; dealings and amounts; economic analysis; true-ups and connected tax effects; other returns and treaties. This permits work allocation without losing central control.
Assign both a fact owner and response owner. Legal can validate the agreement and relationship; accounting the amount; operations the function; the specialist the method; and tax the final answer. Separate roles prevent one department from approving facts it does not control.
Reconcile dealings and amounts
Use the same master table supporting PT-006 and PT-007. Match every ISSIF dealing to the trial balance, subledgers, invoices, Anexo 9, study and local return. Explain aggregation, currency, tax base, VAT, adjustment and classification differences. Do not insert a manual spreadsheet with no source.
Check income and deductions, but also zero-value dealings, financing, guarantees, assets, capitalizations and restructurings. A format can request tax values even where no cash moved. Absence of an invoice does not establish absence of a transaction.
Control signs and units. Some fields require amounts without punctuation; others require percentages or yes/no answers. Software validation catches formatting errors, not conceptual errors.
Method and outcome
The ISSIF method should agree with the study and Anexo 9. Where a dealing uses more than one analysis, document how it is represented in the format. Method selection does not follow from the account name. Tested party, indicator and range should be those in the final file.
Questions about arm’s length conditions require knowledge of whether the outcome was within range or adjusted. Do not answer yes merely because a study exists. Review the result by dealing and execution of true-ups. If a conclusion remains open at annual-return filing, document the treatment and effect.
Questions about unique and valuable contributions come from functional and intangible analysis, not transaction size. Retain the reasoning and, where appropriate, include a precise additional explanation.
True-ups and connected tax effects
A true-up can affect income tax, VAT, electronic invoices, customs and other forms. ISSIF may ask whether VAT values or recoverable VAT changed because of a transfer pricing adjustment. Coordinate the response with accounting and indirect-tax specialists.
Distinguish real and virtual, voluntary and primary, and corresponding adjustments. Confirm amount, date, journal entry, invoice or credit note, amended return, notices and deduction. Do not report a scenario that remained only in the study as executed.
Maintain an impact matrix by return. If the adjustment changes after Anexo 9 or the local return, assess amendments before closing ISSIF. Do not “solve” ISSIF using a different amount without correcting or explaining earlier sources.
ISSIF field-source-owner matrix
| Family | Primary source | Cross-check | Owner |
|---|---|---|---|
| ISSIF requirement | Article 32-H and taxpayer data | Annual return | Tax |
| Relationship | Legal map | Master data and agreements | Legal/tax |
| Dealings | Master table and subledgers | Anexo 9 and local return | Accounting |
| Functions and risks | Interviews and processes | Agreements and master file | Operations |
| Method and comparables | Study and workpapers | Anexo 9/local return | TP specialist |
| Range and result | Final calculations | Statements and segmentation | Controllership/TP |
| True-up | Memorandum and entry | Invoices, VAT and returns | Tax/accounting |
| Article 76-A | Applicability memo and receipts | Calendar | Tax |
| Foreign residents | Payments and agreements | Withholding and treaties | International tax |
Zugzwang’s ISSIF TP Reconciliation assigns sources and owners to each field, reconciles data to the study and returns, and documents differences before the annual return is signed.
Review process
First confirm the applicable format and version. Second finalize the applicability sheet. Third load the question catalog into the matrix and assign owners. Fourth freeze and reconcile the transaction table. Fifth review technical questions against the file. Sixth cross-check previously filed returns. Seventh validate the file and document approval.
Use an independent reviewer. Sample high-value and high-risk dealings, but also new transactions and mandatory negative answers. Reproduce both the amount and conclusion from source evidence.
Retain the source file, submitted version, annual-return receipt, matrix, approvals and evidence. For an amendment, record which fields changed and why.
Common errors
The principal error is delegating ISSIF entirely to the annual-return team without involving the transfer pricing specialist. Others include copying prior-year answers, using preliminary amounts, confusing Article 76-A obligations, reporting another method, ignoring domestic dealings and answering adjustment questions without reviewing VAT.
Teams also confuse “a study exists” with “the dealing is arm’s length,” or “CbCR does not apply” with “no information return applies.” The schedules are interdependent: an answer should be compatible with the rest of ISSIF and external files.
Post-filing actions
Review the receipt and submitted version. Compare them with any study completed later. If a true-up or classification changed, assess the annual return, ISSIF, Anexo 9, local return and other tax effects. Document the decision even where no amendment is made.
For the next fiscal year, retain the matrix and mark stable, variable and new fields. Refresh sources, not just answers. Efficiency comes from reusable traceability, not copying the prior filing.
Questions the CFO should resolve
Before signing the annual return, the CFO should know which entities file ISSIF, which controlled dealings are material, whether true-ups remain open and whether amounts agree with returns already submitted. Management should also understand judgmental answers involving unique contributions, losses, restructurings, treaty benefits or differences against the master file.
The executive summary should show exceptions rather than repeat hundreds of indices. Include the field, issue, amount, owner, evidence and decision. A pending answer is not cured by successful software validation; it is escalated with an owner and date. Signature rests on this governance and the detailed file retained behind it.
Where an external provider prepares ISSIF, management remains responsible for the facts. Establish a process under which the provider raises the question, the competent department answers and tax approves. Avoid forwarded email answers that do not identify who controls the data.
Special review situations
Recurring losses require consistency between the ISSIF answer, functional analysis and management explanation. A restructuring requires review of transferred functions, assets, risks and any compensation. A new loan requires consistent principal, interest, currency, term and method across the financing information, study and foreign-resident schedule.
For services and royalties, confirm not only the amount and method but also withholding, treaty position and evidence of performance or rights. Where a true-up affects VAT, document the indirect-tax decision rather than asking the transfer pricing team to infer it. These cross-functional situations are the reason a field-source-owner matrix is more reliable than a single preparer working through the form sequentially.
Related topics
- PT-004: 2026 calendar.
- PT-005 and PT-006: study and Anexo 9.
- PT-007: local return.
- PT-011: SIPRED.
- PT-016: intercompany inventory.
ISSIF consistency certification
The ISSIF owner should receive a locked related-party matrix with field, source, account, counterparty, amount, method, range, adjustment and documentary reference. Tax certifies treatment; accounting certifies the figure; transfer pricing certifies method and conclusion. Differences from the study or returns are logged with cause, correction and approver.
Test one sample from the captured datum to entry and agreement, and another from intercompany accounts to the questionnaire to detect omissions. Compare balances, accumulated amounts, currency and sign. If an adjustment is recorded after the study was prepared, update every affected output and preserve the bridge between versions.
Closing evidence includes the locked workpaper, completed controls, exceptions, filed version and receipt. ISSIF then ceases to be separate data entry and becomes visible proof that the company governs its intercompany information.
Sources and verification date
- Federal Fiscal Code, current text, Article 32-H.
- Annex 16 of the 2026 Miscellaneous Tax Resolution, published January 19, 2026.
- SAT fiscal year 2025 corporate annual return site.
- Mexican Income Tax Law, current text, Articles 76 and 76-A.
Sources checked on August 2, 2026. Confirm the format guide, taxpayer type and software version.
If ISSIF is being answered from the annual return without a matrix connecting the study, ledger and related-party returns, request a review before filing or amending it.