Intercompany transaction inventory: from the trial balance to a transaction map

Executive answer #

The intercompany transaction inventory is the controlled population of dealings, balances and events between related parties that feeds studies, returns, reconciliations and monitoring. It should not be built by copying last year’s report or asking tax for a list. Begin with the trial balance and subledgers, expand the search through counterparties and documents, and finish with a classification validated by the people who perform the transaction.

The trial balance is essential, but insufficient on its own. A dealing may be spread over several accounts, booked under a vendor that is not flagged as related, netted without cash, accrued without an invoice or embedded in inventory, an asset, equity or foreign-exchange results. Dealings without a separate entry—such as guarantees, free use of intangibles or restructuring decisions—may also exist.

A reliable matrix answers five questions: with whom, what happened, how much and when, how is it supported, and where is it analyzed or disclosed? Every row needs an owner, source and status. The goal is not a very large spreadsheet. It is a single source that traces an account to a return and a return answer back to evidence.

Why inventory comes before analysis #

Articles 76, 179 and 180 of the Mexican Income Tax Law require related-party dealings to be determined and, where applicable, documented under the arm’s length standard. Reproducible compliance is impossible if the population is discovered after methods have been selected. An omitted dealing receives no functional analysis or method, is not reconciled and may be missing from returns.

Inventory also prevents the opposite problem: duplication. A purchase may appear in accounts payable, inventory, cost of sales and customs entries. A loan may appear in bank accounts, interest, foreign exchange and withholding. The matrix should identify the economic transaction and connect its accounting representations without adding each one as a new dealing.

The perimeter is broader than invoices. It includes revenue, expense, assets, liabilities, equity, services without charge, guarantees, licenses, netting, contributions, dividends, restructurings and true-ups. Capture first; then determine whether each item needs pricing, documentation or disclosure.

Five discovery sources #

Trial balance and subledgers #

Extract accounts labelled intercompany, related party, affiliate, parent, subsidiary, current account or with group names. Review income, cost, expense, assets, liabilities, equity, tax, interest and foreign exchange. Include opening balance, movement and closing balance.

Counterparty master #

Cross-check Mexican tax IDs, foreign identifiers, legal names, country and bank beneficiary against the related-party perimeter. Aliases and duplicates are common. One company may have separate customer and vendor codes or change its legal name during the year.

Electronic invoices and foreign documents #

Compare issued and received documents with the ledger. Identify cancellations, credit notes, supplements, documents without entries and entries without documents. For cross-border dealings, link foreign invoice, customs entry, withholding and settlement.

Agreements, treasury and legal records #

The agreement repository reveals loans, licenses, guarantees, cash pools, leases and services that an account name does not describe. Treasury provides settlements, netting and balances. Minutes and approvals reveal capitalizations, dividends and reorganizations.

Interviews and operating systems #

Procurement, sales, IT, human resources, supply chain and plant teams may identify benefits or functions invisible in finance. Tickets, orders, inventory and time systems validate performance. Interviews do not replace data; they explain and complete the extraction.

Nine-step build method #

1. Freeze the perimeter. List entities and related periods, country, identifier and relationship.
2. Extract accounting. Obtain trial balances, subledgers and account masters without filtering only known accounts.
3. Normalize counterparties. Resolve aliases, codes and name changes under a stable identifier.
4. Detect candidates. Use accounts, counterparties, narratives, banks, invoices and agreements.
5. Group by dealing. Separate accounting representations from the underlying economic transaction.
6. Classify. Goods, services, finance, intangibles, lease, equity, reimbursement, guarantee or extraordinary event.
7. Reconcile. Explain invoice, accrual, settlement, currency, balance and disclosure.
8. Validate with the business. Confirm conduct, functions, beneficiaries, assets and risks.
9. Approve and version. Close the population, exceptions, owner and subsequent changes.

Every step leaves evidence. A final population without extraction records, rules and decisions cannot be reproduced next year.

Recommended matrix #

The matrix can begin in a controlled spreadsheet. At higher volume, automate extraction and matching while preserving human approval of relationship and characterization.

If the annual report begins with a list circulated by email, build a reproducible matrix from the trial balance before selecting methods or completing forms.

Useful detection rules #

One rule finds counterparties marked as related; another finds group names and accounts. A third compares bank beneficiaries; a fourth detects recurring balances or movements without invoices. Search narratives for management fee, recharge, royalty, loan, interest, support, allocation, shared cost, tooling and guarantee.

Rules create candidates, not conclusions. A similar name may be unrelated; an unmarked counterparty may be controlled. Resolve each exception with evidence and feed the answer back into master data. Tracking false positives and newly discovered dealings improves the control.

Use thresholds for review priority and proportionate documentation, not to erase the population. Multiple small entries may form one material service or balance. Events without an amount, such as an unpriced guarantee, need a qualitative record.

End-to-end reconciliation #

The first bridge connects opening balance, debits, credits and closing balance by counterparty. The second connects accrual, invoice and settlement. The third translates transaction currency to functional currency and foreign-exchange result. The fourth compares accounting with the report and returns.

Use controlled difference reasons: timing, exchange rate, tax, cancellation, reclassification, netting, accrual, true-up or error. Avoid free-text labels such as “under review.” Each difference needs an amount, owner and due date.

For goods, reconcile volume and customs entries; for services, costs and allocation keys; for loans, principal, interest and withholding; for royalties, base and rate; for adjustments, calculation, document and corresponding effect. Reconciliation should reflect the nature of the dealing.

Items that commonly escape #

Accounts not flagged as related. The vendor was created before joining the group or uses a trade name. Cross-checking the legal perimeter reveals it.

Balances without movement. An old loan has only an opening balance and disappears from a movement-only extract. It may still need interest, testing and disclosure.

Services without charge. Employees of another entity support Mexico without an invoice. No amount does not mean no characterization decision.

Netting. Revenue and expense are offset and only the net is booked. Analysis may require gross amounts and separate dealings.

Balance-sheet transactions. Assets, inventory, receivables, contributions or capitalizations disappear from a profit-and-loss-only search.

External pass-throughs. A third party invoices one group company, which reallocates the cost. Determine who received the benefit, controlled the purchase and added value.

Governance and monthly close #

Finance owns extraction; tax defines perimeter, classification and requirements; legal maintains agreements; treasury validates cash and financing; operations confirms conduct; master data fixes labels. The CFO approves material exceptions and policy changes.

Load movements and resolve new counterparties monthly. Validate classification and test margins, rates or balances quarterly. At year-end, lock a version, document later adjustments and issue bridges to the report and returns. Never silently overwrite the population used for filing.

Useful metrics include counterparty coverage, reconciled percentage, dealings without agreements, overdue evidence, aged differences and time to add a new entity. The number of rows does not measure quality.

Common errors #

1. Reusing the prior-year inventory without a complete extraction.
2. Searching only accounts named intercompany.
3. Depending on names without a stable tax or legal identifier.
4. Excluding balance sheet, equity and unbilled dealings.
5. Counting an invoice, cost and customs entry as three transactions.
6. Netting revenue and expense without preserving gross amounts.
7. Applying thresholds before classification.
8. Allowing free-text transaction types.
9. Reconciling total value but not counterparty and nature.
10. Changing the filed matrix without history.

Expected output #

The Intercompany Transaction Map provides a population by entity, counterparty and dealing; accounting bridges; links to agreements and evidence; method and reporting requirements; a gap rating; and owners. It becomes the common input for functional analysis, studies, Annex 9, Local File, ISSIF, SIPRED and monitoring.

Related topics #

• PT-001: obligations diagnostic.
• PT-013 and PT-014: domestic and foreign dealings.
• PT-015: evidence calendar.
• PT-017: functional analysis.
• PT-100: intercompany control maturity.

Intercompany-population certification #

At monthly close, the data owner compares the related-party register with vendors, customers, banks, manual journals, receivables, payables and electronic invoices. Matches are classified by transaction family; possible new relationships go to legal and tax. Do not exclude an account by name: reimbursements, assets, dividends, guarantees and offsets may sit outside familiar intercompany accounts.

The matrix retains entity, counterparty, relationship, account, currency, flow, agreement, invoice, owner, method, return and evidence. Reconcile movements and balances, explain eliminations and keep a list of no-charge dealings. A second reviewer samples from ledger to matrix and matrix to documents.

Every addition or removal requires a date and approval. The locked file becomes the source for studies, returns, monitoring and audits. Without this control, automation merely processes an incomplete population faster.

Sources and verification date #

Report monthly coverage through reconciled value, unmatched accounts, unresolved counterparties and overdue agreements. Percentages should use the full accounting population as denominator. Management approves exceptions with an owner and due date; the following close retests them. This makes completeness measurable rather than an unsupported assertion.

• Mexican Income Tax Law, current text, Articles 76, 76-A, 179 and 180.
• Mexican Federal Tax Code, current text, Articles 28 and 30.
• 2026 Miscellaneous Tax Resolution, subject to amendments.
• SAT Multiple Information Return.

Sources checked on August 2, 2026. Classification and requirements depend on the facts, entity, fiscal year and applicable form.

Request an Intercompany Transaction Map to turn trial balances, counterparties and documents into a controlled population ready for analysis and compliance.