What Auditors Look for in Tax Compliance Processes

Auditors reviewing excise or indirect tax compliance typically focus on six areas: source records, a traceable path from data to return, accurate calculations and classifications, reconciliations that explain differences, audit-ready electronic records, and evidence the filing process was followed.

An indirect tax audit can extend beyond the amount reported on a return. State authorities set their own rules, but most require businesses to maintain records that support reported sales, purchases, exemptions, credits, inventory, and tax liabilities.

For tax teams, the main question is straightforward: can the organization link the amount on the return to the records and decisions that support it?

That question is getting harder to sidestep. EY’s 2025 Tax Risk and Controversy Survey found that 90% of tax leaders expect disputes to increase, driven by enforcement activity, global tax reform, and rising transparency demands.

Records Must Support the Return

Excise and indirect tax authorities place the recordkeeping burden on the taxpayer. Requirements vary by tax type and jurisdiction, but supporting records for tax typically include:

• purchases and sales
• Product types and classifications
• Inventory activity
• Credits, allowances, and discounts claimed
• Documentation supporting nontaxable use

The return is only one part of the audit record. Supporting documentation must show where the reported amounts came from and why that tax treatment applied.

Excise-taxed businesses are especially exposed here. Troutman Pepper notes that excise taxes, such as those on tobacco, require accurate bookkeeping and regular reporting, and that state audits rarely close without an alleged deficiency.

Auditors Trace Data from Source to Return

An audit trail is the documented path connecting a company’s source data to the final figures on its tax return.

Auditors examine how information moved from operational and accounting systems into the filing. That includes the original transaction population, source files, tax treatment mappings, manual adjustments, reconciliation steps, and the final data used on the return.

Each handoff between systems is a place that the trail can break. Deloitte’s tax controversy practice notes that resolving a dispute efficiently depends on the document management tools a team already has in place.

A traceable process answers three questions:

1. Where did the data originate?
2. What changed before it reached the return?
3. Who reviewed those changes?

When those answers live across disconnected systems and inboxes, the tax team has to reconstruct the filing process during the audit. When they’re documented as the work happens, the organization already has that record.

Auditors Review Calculations, Classifications, and Exemptions

Auditors verify that a company applied the correct tax rate, exemption, credit, or deduction to each transaction, not just the total amount reported.

Reported tax depends on more than the transaction amount. Auditors also review how products, customers, and transactions were classified.

For excise tax companies, treatment may hinge on product type, volume, use, destination, or the party responsible for the tax. For sales and use tax, an exempt or resale transaction needs a valid certificate or other required documentation.

Rules vary across jurisdictions, adding a layer of jurisdictional complexity. The tax team should be able to connect any material tax treatment to the applicable rule, its effective date, and supporting documentation.

Showing which classification was used isn’t enough. The team also needs to show why that classification fit the transaction and reporting period.

Auditors Look for Reconciliations and Explanations

A reconciliation shows an auditor what data was compared, what differences turned up, and how the tax team resolved them.

A tax return should align with the organization’s operational and financial records, but totals won’t always match without explanation.

A useful reconciliation shows what was compared, flags differences, and documents how those differences were resolved. That’s evidence that the tax team reviewed the filing for completeness and accuracy before submitting it.

Electronic Records Must Stay Audit-Ready

Electronic tax records carry the same recordkeeping obligations as paper records, plus the added requirement that they stay retrievable and connected to the filing they support.

Record format doesn’t change the taxpayer’s responsibility to maintain it.

Electronic records need to be accessible, usable, and connected to the relevant filing for the full retention period. A folder of disconnected spreadsheets and PDFs stores documents, but it doesn’t preserve the link between source data, adjustments, the return, approval, and payment.

An audit-ready record lets the team identify the entity, jurisdiction, tax type, filing period, source file, and final filed version without relying on one key person dependency.

Auditors Look for Evidence the Process Was Followed

Auditors check filing history for proof that someone prepared the return, someone else reviewed it, and required approvals happened before the filing went out. A completed return doesn’t prove the organization followed a controlled compliance process.

Filing history should show who prepared the return, who reviewed it, what adjustments were made, whether required approvals happened, and when the filing and payment were completed.

Inadequate Records Can Change the Audit Outcome

Businesses with inadequate records risk an estimated audit assessment, added penalties and interest, and in some states, suspension of their license to collect tax.

New York offers a clear example. Its Department of Taxation and Finance states that a vendor with inadequate records may face an estimated audit methodology, added penalties and interest, criminal penalties for willful violations, and suspension or revocation of its Certificate of Authority.

Retaining records isn’t enough. The business must locate, retrieve, and connect them to the return under examination.

Build Audit Readiness Into the Compliance Workflow

Building Audit readiness is most effective when documentation is captured as the work happens, not piecemealed after an audit notice arrives.

That governance work pays off directly. EY’s tax policy team reports that authorities are increasingly grouping companies by risk level, and businesses with strong governance frameworks tend to face reduced audit frequency compared with those showing weaker controls.

How Compliance Intelligence Documents The Compliance workflow

ComplyIQ centralizes compliance obligations, assigned responsibilities, compliance workflows, approvals, supporting documentation, escalations, and activity history. It maintains an audit trail of task completion, approvals, due-date changes, and workflow activity, so teams preserve evidence of how each obligation was managed.

For excise and indirect tax teams, it connects the filing obligation to the process around it. Leaders can see who owns the work, whether reviews and approvals happened, what documentation exists, and where an obligation is delayed or incomplete.

ComplyIQ provides the governance layer that keeps responsibilities, documentation, approvals, and filing history connected to the obligation. That lets tax teams maintain a controlled compliance record year-round instead of rebuilding one when an auditor comes calling.

This analysis is intended for informational purposes only and is not tax advice.  For tax advice, consult your tax adviser. See the full disclaimer here.