The books can close on time while an important question remains unanswered. Should a new payment be recorded as revenue, a customer advance, a shareholder loan, or capital? Each answer changes the accounting entry, CFDI, tax timing, and documents the company needs.
You may need a separate review to answer that question, especially if the transaction is new to the business. A tax and accounting consultant can examine the contract, payments and records, then explain the treatment and the steps needed to apply it. Confirm whether that work is included in your monthly accounting agreement.
Before hiring, agree on the question the consultant will answer. Ask which records they need and what you will receive at the end, such as a calculation, a written recommendation or corrected accounting entries.
Know which service you are buying
| Need | Appropriate service | Expected output |
|---|---|---|
| Record the month and file routine returns | Monthly accounting and compliance | Reconciled close, workpapers, returns, and receipts |
| Answer one defined tax question | Tax advisory | Written answer with facts, rule, assumptions, and action |
| Diagnose repeated differences | Fiscal and accounting consulting | Root-cause analysis, quantified findings, and implementation plan |
| Respond to a formal proceeding | Tax controversy support or legal representation | Procedural strategy, evidence file, and authorized response |
| Improve reports and controls | Accounting process project | New process, account design, owners, and verification test |
One provider may offer several of these services. The proposal should still separate them. An ordinary monthly fee rarely covers an unlimited reconstruction, a refund claim, or a formal defense.
Events that justify a consulting project
The business does not need to be large. It needs a decision whose cost or repetition justifies analysis.
| Event | Question to resolve |
|---|---|
| New revenue stream | When is revenue recognized, which tax applies, and what CFDI documents it? |
| Financing or capital injection | Is the money debt or equity, and which approvals and records support it? |
| New partner or related company | What changes in control, pricing, contracts, and tax reporting? |
| Payroll expansion | Which payments are salary, benefits, reimbursement, or contractor fees? |
| Inventory or fixed assets | How will purchases, depreciation, cost, and disposals be tracked? |
| Foreign customer or supplier | Which source, withholding, VAT, customs, currency, and treaty questions require review? |
| Repeated CFDI and bank differences | Which process creates the mismatch and which filed periods were affected? |
| SAT communication | Is it an invitation, request, or formal act, and who should respond by which date? |
| Sale, merger, or closure | What must be reconciled, valued, filed, retained, and handed over? |
Some events require a tax lawyer, customs specialist, labor counsel, or valuation professional as well as an accountant. Consulting should identify that boundary early instead of pretending one person covers every specialty.
Start with a precise question
If you are unsure how to describe the project, start with the transaction or recurring problem that concerns you. These requests give the consultant enough detail to discuss the work:
- Determine whether customer deposits received before delivery were recorded and invoiced in the correct period.
- Reconcile revenue reported in monthly returns to issued CFDI and bank collections for January through June.
- Compare a shareholder loan with a capital contribution, including tax, accounting, corporate, and cash effects.
- Design the payroll evidence needed for travel reimbursements and identify corrections for open periods.
Specify the periods and transactions to review. That helps the consultant estimate the fee and lets you check whether the report answers what you asked.
Prepare a diagnostic file
Agree on which records the project needs, then send them through a secure channel with a file list. Depending on the question, these may include:
- current articles of incorporation and ownership records;
- SAT tax situation certificate;
- current tax compliance opinion;
- filed returns, receipts, and payment records for the selected period;
- trial balance, general ledger, and account reconciliations;
- issued and received CFDI metadata or XML for the selected transactions;
- bank statements and collection detail;
- contracts, purchase orders, payroll records, or corporate approvals tied to the question;
- notices, invitation letters, or formal acts with their notification dates;
- a list of known differences and prior explanations.
A positive tax compliance opinion is useful evidence of the status shown in SAT systems. The SAT expressly states that it is not a favorable resolution on the accuracy of tax calculations or amounts paid. It cannot replace the diagnostic.
Limit access to what the project needs. Use a document index, named folders, and a log of files delivered. Tax consulting is not a reason to scatter the e.firma private key across email threads.
Require findings that can be reproduced
A finding should contain enough detail for another accountant to test it:
| Field | What it should say |
|---|---|
| Issue | The exact transaction, account, return, or control affected |
| Population | Period and records reviewed |
| Evidence | CFDI, bank entry, contract, ledger, or filing used |
| Criterion | Tax rule, accounting policy, or control requirement applied |
| Difference | Amount, count, deadline, or missing document |
| Effect | Tax, cash, reporting, operational, or legal consequence |
| Recommendation | Corrective action and any alternatives |
| Owner | Person responsible for the decision or task |
| Due date | Legal deadline or agreed project date |
| Verification | Record that will prove completion |
For example, a report might identify seven April deposits totaling MXN 284,000 for which no invoice, customer advance record or loan agreement was found. It should list those deposits so you can check them and look for the missing documents.
Separate facts, assumptions, and conclusions
A consulting memo should mark each one:
- Facts come from contracts, CFDI, ledgers, bank records, filings, and interviews that the client confirmed.
- Assumptions fill a gap temporarily and must state what would change if the assumption is wrong.
- Criteria identify the tax provision, accounting policy, or company rule used.
- The conclusion answers the question under those facts and criteria.
- The action states what to record, issue, file, approve, pay, or preserve.
This separation matters when the company has incomplete records. A neat answer based on an untested assumption is still a weak answer.
Quantify alternatives before recommending one
For a decision project, ask for a comparison in pesos and dates:
| Scenario | Current treatment | Alternative A | Alternative B |
|---|---|---|---|
| Tax due and payment date | Document current treatment | Document alternative | Document alternative |
| VAT and withholding | Document current treatment | Document alternative | Document alternative |
| Accounting entry | Document current treatment | Document alternative | Document alternative |
| CFDI or filing changes | Document current treatment | Document alternative | Document alternative |
| Cash effect | Document current treatment | Document alternative | Document alternative |
| Corporate or contract documents | Document current treatment | Document alternative | Document alternative |
| Implementation cost | Document current treatment | Document alternative | Document alternative |
| Main uncertainty | Document current treatment | Document alternative | Document alternative |
Do not accept a promised tax saving without its starting point, assumptions, and implementation steps. A lower tax number can be useless if the proposed treatment conflicts with the contract or cannot be supported by the actual flow of money.
Turn recurring answers into a company rule
If the same question appears every month, the final deliverable should become part of the close process. A short transaction policy can state:
- which operations it covers;
- who approves the transaction;
- which contract and CFDI are required;
- which accounting entry is used;
- when tax is recognized;
- which bank or operational evidence is retained;
- who reviews the first three applications;
- when the policy must be reconsidered.
Ask the consultant and the person responsible for the monthly close to apply the instructions to a real transaction. Check whether the required documents are available and whether the team can follow the steps without further explanation.
Decide which findings to address first
Use four questions:
- Is there a legal or filing deadline?
- Can the issue change tax, cash, or the validity of a document?
- Does it repeat across many transactions?
- Does another business decision depend on it?
An unsupported shareholder loan due in a formal response may outrank a large but well-documented reconciliation difference. A software redesign can wait if the company still has unfiled returns.
The action plan should also separate containment from correction. Stopping new errors this week may be possible even when reconstructing two prior years will take months.
Define implementation before the engagement starts
Before accepting the proposal, confirm who will apply the recommendations. You can divide the responsibilities as follows:
| Stage | Consultant | Client |
|---|---|---|
| Decision | Present criteria, alternatives, and recommendation | Approve the selected treatment |
| Design | Draft entries, forms, controls, and document requirements | Confirm operational feasibility |
| Correction | Prepare the correction package and affected-period list | Provide authorization, signatures, and payment |
| Training | Walk through the new process with sample transactions | Assign owners and attend |
| Verification | Test the first close or selected sample | Supply records and correct failed steps |
If implementation is excluded, request a handoff package detailed enough for the monthly accountant to execute.
Know when legal advice is required
An accountant can analyze records and tax calculations. Legal counsel should review matters involving formal defense, contract interpretation, privilege, shareholder disputes, labor classification, or procedural rights.
The line is especially important after a SAT communication. Before replying, classify the document, record the notification date, preserve the complete file, and decide who has authority to respond. A friendly email from an accountant is not a substitute for a procedural strategy when a formal act is involved.
Measure whether the project worked
Choose measures tied to the original question:
- unmatched revenue amount before and after the project;
- returns or periods corrected;
- days required to close the month;
- number of recurring exceptions;
- tax and cash forecast variance;
- policies implemented and tested;
- open findings past their due dates.
At the next close, check whether the agreed treatment was applied and whether the original problem recurred. Use the results to identify any further corrections or training the team needs.
Compare proposals on the same project
Ask each provider to price the same period, population, deliverables, implementation work, meetings, and verification. Our guide to accounting service costs includes an annual-cost sheet, security questions, and handoff terms.
How Fintax can support the project
Fintax can review a specific tax or accounting issue, explain the findings and help apply agreed corrections. Describe the transaction or period you want reviewed. If the review reveals more work, agree on the additional scope and fee before proceeding.
Frequently asked questions
What is fiscal and accounting consulting?
It is a defined project that analyzes a tax or accounting decision, repeated problem, or control failure and produces documented criteria, quantified findings, and an action plan.
How is consulting different from monthly accounting?
Monthly accounting records transactions, reconciles the period, and files recurring obligations. Consulting investigates a question, compares treatments, or redesigns a process. One may reveal the need for the other.
What should a consulting report include?
It should state the question, period, records reviewed, facts, assumptions, applicable criteria, quantified findings, alternatives, recommendation, actions, owners, due dates, and verification method.
Does a positive SAT compliance opinion mean the tax calculations are correct?
No. The SAT says the opinion reflects the status in its systems and is not a favorable resolution on the calculation or amount of taxes declared or paid.
Complexity appears in the handoffs
Growth usually creates risk where sales, payroll, purchasing, treasury and accounting exchange information. List those handoffs and note which document closes each one. The first consulting priority should be the gap that can change a filing or cash decision, rather than redesigning every process at once.
