Executive answer
For an enterprise qualifying as a maquila operation under Article 181, Article 182 allows compliance with Articles 179 and 180 and protects the foreign principal’s no-permanent-establishment position when taxable profit is at least the greater of 6.9% of total assets used in the operation or 6.5% of operating costs and expenses computed under Article 182.
In 2026, closing fiscal year 2025 requires more than multiplying two totals. First confirm that the operation meets the tax definition of maquila. Then build asset, cost and expense bases using the correct inclusions, exclusions, averages, currencies and ownership; compare results; recognize required profit; reconcile the annual return and file DIEMSE within the applicable period.
The most costly error is treating the greater result as an isolated number. The statute connects computation, evidence, information return and the permanent-establishment condition. Missing foreign inventory, a wrongly excluded account or an inconsistent DIEMSE can affect more than the maquiladora’s tax.
Conceptual calculator
| Variable | Formula | Source |
|---|---|---|
| Asset base | Mexican + foreign + related assets used, under Article 182 | inventory, fixed assets, ownership, use, currency |
| Result A | Asset base × 6.9% | Section I workpaper |
| Cost base | included operating costs and expenses, net of exclusions | ledger, payroll, services, investment |
| Result B | Cost base × 6.5% | Section II workpaper |
| Minimum profit | greater of A or B | approved comparison |
| Required adjustment | minimum profit minus preliminary taxable profit, if positive | close and returns |
This table does not replace the statute. Each base has specific rules.
Step zero: confirm qualification
An IMMEX program is not sufficient. Article 181 requires, among other elements, goods supplied under a maquila agreement, temporary import and return; productive revenue exclusively from maquila operations; treatment of non-temporarily imported goods; and machinery-and-equipment conditions, including the statutory foreign-ownership percentage in the relevant case.
Prepare an annual eligibility memorandum covering the program, agreement, customs entries, flows, revenue, machinery, ownership and activities. Review domestic sales, additional services, development, repair, storage and acquired assets. A change during 2025 may affect the period or model.
Do not use Safe Harbor to cure an operation failing Article 181. Qualification and result are sequential tests.
Asset base overview
Section I includes total assets used during the year, whether owned by the Mexican resident, foreign resident or related parties, including assets granted for use. Identify territory, full or partial use, ownership and valuation method.
Foreign inventory requires monthly averages and valuation and conversion rules. Foreign fixed assets follow statutory remaining-value, date, percentage and floor provisions. Mexican assets use procedures prescribed in applicable rules. Exclusion of certain leased assets is conditional.
Do not take total balance-sheet assets or customs records without reconciliation. The tax base combines Mexican information with the foreign owner’s records. PT-053 develops the asset inventory and bridge.
Cost and expense base overview
Section II begins with operating costs and expenses incurred by the Mexican resident under financial reporting standards and includes certain foreign-resident expenses under conditions. It excludes specified items such as merchandise purchased for the foreign resident’s own account, inflation effects, financing expenses and certain extraordinary or nonrecurring expenses. Investment deductions follow the Law.
An account is not included or excluded by name. Classify nature, beneficiary, connection to maquila, incurring entity and support. Foreign-personnel costs can require days, salary and special rules. PT-054 develops the ledger bridge.
Reconcile the base to statements, cost of sales, payroll, group accounts and services. Document reclassifications and do not label a cost nonrecurring without meeting the definition.
2025-to-2026 timeline
| Moment | Action |
|---|---|
| monthly in 2025 | assets, inventory, costs, FX, ownership and use |
| January-February 2026 | close bases, reconciliations and adjustment |
| March 2026 | annual corporate return under applicable calendar |
| through June 2026 | DIEMSE under Article 182 and current form/rules |
| afterward | file, permitted corrections and 2026 monitoring |
SAT’s corporate annual-return page listed March 31, 2026 for the general regime’s 2025 return. Article 182 requires DIEMSE no later than June and conditions the article on filing and reflecting the minimum profit. Confirm the day, form version and channel; do not invent a day from “month of June.”
The option notice and DIEMSE have descriptions and authorities that should be reviewed separately. Retain acknowledgments.
Zugzwang can review eligibility, bases, result, adjustment, annual return and DIEMSE as one Maquila Safe Harbor Readiness workstream.
Profit reconciliation
Begin with taxable profit before Safe Harbor and bridge to the greater amount. Align maquila service income, costs, deductions, nondeductible items and other activities. If the company performs permitted non-maquila activities, segment them; Article 182 covers only the maquila operation.
Reconcile taxable, accounting and operating profit. Minimum profit does not necessarily mean additional invoice income equal to the difference. Determine contractual, accounting and tax mechanics. Where an intercompany true-up is required, coordinate tax invoicing, currency, VAT, withholding or customs based on facts.
Do not adjust only in the return while agreements and accounts show another remuneration. Keep before-and-after bridges and foreign counterparty approval.
Illustrative case
A maquiladora has an asset base of MXN 1.2 billion and a cost base of MXN 900 million. Asset result is MXN 82.8 million; cost result is MXN 58.5 million. Minimum profit is MXN 82.8 million. If preliminary taxable profit is MXN 76 million, the team analyzes a MXN 6.8 million shortfall.
Before recording, it finds MXN 100 million of omitted foreign inventory, which increases Result A by MXN 6.9 million. It also finds MXN 20 million of finance expense wrongly included in B; removing it lowers Result B by MXN 1.3 million, although A remains higher. Correct profit depends on both corrections.
The example is illustrative and does not reproduce every valuation, currency or tax rule.
Asset evidence
Retain an asset list showing owner, location, use, date, currency, cost and valuation. For inventory retain monthly opening and closing balances and the owner’s accounting. For foreign fixed assets retain acquisition, hypothetical depreciation, months, FX and floor. For Mexican property retain register and deduction.
Reconcile to customs entries, Anexo 24 or trade controls, insurance, maintenance and physical walkthroughs. Investigate idle, in-transit, shared, retired or interplant assets. Presence and use matter.
Obtain confirmation from the foreign resident and related parties. Validate an owner’s unsigned spreadsheet before relying on it.
Cost evidence
Prepare an account-by-account catalog showing inclusion rule, source and owner. Reconcile payroll, benefits, services, energy, rent, maintenance, tax depreciation and foreign expenses. Identify excluded goods and financing expense.
For nonrecurring items document nature, reporting standards, reserves, provisions and liquid funds where the text requires. Do not adopt a policy excluding every launch cost, severance or scrap item.
Sample invoices, entries and payments. Expenses incurred abroad require support and a direct relationship where applicable; do not copy global allocations without evidence.
DIEMSE consistency
The information return must reflect taxable profit at least equal to the greater result. Prepare a field-source-owner map and validate asset, cost, revenue, foreign-resident and period data. An acknowledgment does not prove accuracy.
Reconcile DIEMSE to annual return, ledger, study, agreement and foreign-asset evidence. Resolve differences before filing or document treatment under applicable rules. Control form version and submission backup.
The statute states that failure to file or reflect the required outcome prevents application of Article 182. Escalate errors immediately and assess available correction routes with advice.
Permanent-establishment connection
Article 181 links protection to the treaty, its requirements and compliance with Article 182. Do not describe Safe Harbor only as a minimum margin. Also retain residence, agreement, property, treaty, applicable mutual agreements and flows.
The foreign principal should understand which information it provides and which risk the regime addresses. The responsibility matrix should cover assets, inventory, documents and true-up approval.
Monthly controls in 2026
Do not wait for the next close. Forecast both bases monthly using new assets, inventory, FX, costs and profitability. Show which test dominates and sensitivity. A mix change can switch the result.
Set alert thresholds: unreported foreign asset, unclassified account, profit below greater result, non-maquila revenue, unconfirmed ownership or ownerless DIEMSE. Close exceptions with dates.
A dashboard does not replace the legal workpaper, but it allows correction of data and policy before December.
Adversarial review
Ask: did the operation meet Article 181 all year; are all assets included; is ownership proven; are averages and FX correct; were costs classified under the text; are other activities separated; does profit agree; do annual return and DIEMSE reconcile; are acknowledgments retained; does the foreign resident have its file?
Every yes should link evidence. Someone other than the base preparer should perform the review.
Minimum deliverable
The file includes an eligibility memorandum, agreement, program and customs documents, asset map, 6.9 and 6.5 workpapers, reconciliations, profit model, true-up, annual return, DIEMSE, acknowledgments, foreign-principal evidence, review and update calendar.
Data governance across Mexico and the foreign principal
The asset base often depends on information outside the Mexican ERP. Formalize an owner certification listing inventories, acquisition costs, dates, depreciation and currency. Define delivery date, format, owner and review. Certification should cover ownership changes, plant transfers and disposals.
Mexico should return exceptions: assets without customs support, duplicate serials, unknown currency, zero value, date after use or differences against maintenance records. The foreign owner confirms or corrects with evidence. Preserve both versions and a change log.
For costs incurred abroad use an equivalent process covering service, Mexican obligation, personnel, days and support. A group allocation does not replace evidence required by Article 182.
True-up mechanics
Before year-end define whether remuneration adjusts through an additional invoice, credit note, journal entry or another permitted mechanism under the facts. The agreement should specify formula, currency, date and responsibility. An amount recognized only on the tax return may not reconcile with revenue and intercompany accounts.
Compute the adjustment using frozen base versions. Record both parties’ approval and prove collection or balance. Analyze FX between computation, invoice and payment and determine whether it belongs to remuneration or treasury.
Where the adjustment changes service value, review VAT and other effects. Where it interacts with imports, coordinate customs without assuming Safe Harbor and customs value are equivalent. Document the conclusion by tax.
Review package
Prepare a one-page summary showing qualification, Base A, Base B, greater result, preliminary profit, adjustment, final profit, annual return, DIEMSE and acknowledgments. Each figure should link to a controlled workpaper. Add the ten largest differences and their resolution.
A reviewer should recalculate percentages, sample inventory and fixed assets, test cost accounts and rebuild profit from the ledger. Compare with the prior year and explain movements, particularly a change in the dominant test.
CFO decisions
The CFO approves more than tax. Decisions include capital, charge timing, foreign-principal data quality and resources for monthly control. Provide scenarios showing new equipment, inventory, cost inflation, FX and ramp-up effects.
Where projected profit is close to the greater result, establish a reasoned operating buffer and adjustment dates. Do not add an arbitrary margin; quantify volatility and error cost. The decision should remain consistent with the agreement and business reality.
Change management during the year
Require plant, engineering, customs, procurement and HR to notify tax before material changes. New equipment, owner transfers, product lines, foreign personnel or domestic sales can affect eligibility and bases. Add tax review to capital-expenditure and contract workflows.
Keep an event log with date, description, owner, affected article, data change and resolution. Review it monthly. A change discovered during the annual computation is harder to support and may already have affected customs or invoicing.
If the maquiladora begins another activity, create cost centers and asset tags before launch. Segmentation reconstructed afterward tends to rely on broad allocations that are difficult to defend.
Error handling
Distinguish data error, classification judgment, omitted transaction and late filing. Freeze the original, document discovery and quantify every affected output. Obtain legal advice on available correction mechanisms; do not assume that correcting one return automatically preserves Article 182.
Root-cause the issue and change the process. For example, an omitted foreign mold may require an interface between maintenance and the foreign fixed-asset register, not merely another spreadsheet line. Track remediation through the next cycle.
Sources and cutoff
This article was verified as of August 2, 2026. Consult the current Mexican Income Tax Law, Articles 181 and 182, the SAT Safe Harbor notice page, the SAT 2025 corporate annual-return page and the OECD Mexico profile updated July 2025. Verify current regulations and forms.
Zugzwang’s Maquila Safe Harbor Readiness integrates qualification, assets, costs, profit, adjustment, annual return and DIEMSE in a reproducible file.