Amazon Marketplace Reconciliation Using OMS

Amazon marketplace reconciliation using OMS helps finance teams compare internal order data with Amazon reports, settlements, returns, and reimbursements. Instead of reviewing every transaction manually in Excel, teams can map files once, run reconciliation, and review matched, partially matched, unmatched, and skipped records in a structured workflow.

This use case is common for eCommerce brands and marketplace finance teams that need to understand which Amazon transactions have been recorded correctly in the order management system, which ones are missing, and where amounts differ because of fees, returns, deductions, or timing differences.

Why Amazon marketplace reconciliation matters

Amazon data and OMS data rarely line up perfectly on the first pass. The two systems may use different file structures, reference fields, and settlement logic. Finance teams often need to compare:

• order-level sales data from the OMS
• Amazon marketplace sales or invoice reports
• settlement or disbursement reports
• return reports
• reimbursement reports
• bank statements
• SKU or product master files

When these records are reconciled manually, it is easy to miss exceptions or spend too much time tracing one order at a time. A structured reconciliation workflow gives teams a repeatable process for identifying what matched, what changed, and what needs review.

Side A and Side B in this workflow

Cointab uses a Side A and Side B reconciliation model.

For Amazon marketplace reconciliation using OMS, Side A is usually the internal OMS data and Side B is the Amazon-provided data. Supporting files can also be added to enrich the comparison before matching starts.

Typical files used in Amazon OMS reconciliation

A reconciliation setup can include one or more of the following files:

• OMS order report
• Amazon sales or invoice report
• Amazon settlement or disbursement report
• Amazon return report
• Amazon reimbursement report
• SKU master or product master
• Bank statement
• Other supporting reference files for lookup or enrichment

The exact file set depends on how the finance team wants to compare orders, settlements, refunds, fees, and open items.

How Cointab handles the reconciliation

Cointab follows a structured workflow so the same setup can be reused for future periods.

1. Upload the required Amazon and OMS files.
2. Map key fields such as date, amount, and order or transaction identifiers.
3. Add supporting data if needed for lookups, enrichment, or calculation.
4. Create derived columns when a clean comparison field is required.
5. Run reconciliation manually or on a schedule.
6. Review matched, partially matched, unmatched, and skipped records.
7. Download the Excel reconciliation report.

If a file format changes or a required column is missing, the system can reject the file with a clear message so the issue is visible before reconciliation runs.

What finance teams can reconcile

Amazon marketplace reconciliation is not limited to one report comparison. Teams often need to compare multiple layers of data at once.

Order and payment matching

This checks whether an OMS order appears in the Amazon report with the expected amount and reference details.

Settlement and disbursement review

This compares expected payouts against Amazon settlement or disbursement records to identify differences caused by fees, deductions, refunds, or timing.

Returns and reimbursements

This helps track returned orders, reimbursement entries, and recoveries that may affect net revenue or payout values.

Books and bank alignment

For finance close, Amazon-related receipts may also need to line up with the bank statement and internal ledger entries.

How exceptions are classified

Cointab separates reconciliation outcomes so finance teams can focus on exceptions rather than reviewing everything manually.

This classification is useful for Amazon marketplace reconciliation because many exceptions are operational rather than fully missing. For example, an order may be present in both systems but differ because of a refund, fee, deduction, or amount adjustment.

Common exception patterns in Amazon OMS reconciliation

Finance teams typically use Amazon OMS reconciliation to identify issues such as:

• orders recorded in Amazon but missing in the OMS
• orders recorded in the OMS but not found in Amazon reports
• order amounts that differ between the OMS and Amazon
• settlement values that do not match the expected net amount
• return or reimbursement entries that need follow-up
• records that need supporting data before they can be matched
• rows that were skipped because required fields were missing

These exceptions are easier to review when the report clearly separates matched and unmatched items and provides filters for deeper analysis.

Role of supporting data and derived columns

Amazon marketplace data often needs preparation before reconciliation. Cointab supports optional supporting data such as SKU masters, mapping files, and reference exports that help enrich the primary reports.

Teams can also create derived columns using AI-generated Excel-style formulas. This is useful when the business logic is known, but a clean comparison field needs to be created first.

Examples include:

• a normalized order ID
• a clean transaction reference
• a net amount after deductions
• a delivery or settlement comparison amount
• a lookup-based SKU or channel mapping

Derived columns are recalculated whenever the reconciliation is run, so the setup remains reusable for future periods.

AI-assisted analysis for open items

After structured matching is complete, AI can help analyze remaining open transactions. This is useful when Amazon references are incomplete, descriptions vary, or the business context is not obvious from a simple rule.

AI can help finance teams review:

• why a transaction may still be unmatched
• whether a missing file could explain the gap
• whether a return, fee, refund, or deduction may be involved
• which items need manual review or partner follow-up

If the evidence is not strong enough, the item should remain unmatched rather than being forced into a weak match.

Manual match for exceptions that need review

Some Amazon OMS exceptions require human judgment. Cointab supports manual matching so finance teams can pair transactions when the totals tally and the business context is clear.

Manual matching is helpful when:

• identifiers are incomplete
• partner data is delayed or partial
• the system cannot confidently resolve an exception
• a one-off case needs finance review

Manual matches remain visible in the workflow so teams can audit what was matched automatically and what was matched by hand.

Reuse and automation for recurring Amazon reconciliation

Amazon marketplace reconciliation is usually a recurring process. Once a workflow is configured, it can be reused for future periods instead of being rebuilt every month.

Cointab also supports automation through email, SFTP, or API-based data flow. That means teams can set up recurring reconciliation runs, receive refreshed reports when files arrive, and push reconciliation output to downstream systems when needed.

This is useful for finance operations that need regular reporting across:

• daily order or payout checks
• weekly exception reviews
• monthly close
• marketplace settlement tracking
• audit preparation

Reconciliation dashboard and report history

Completed reconciliations remain available on the dashboard for future reference. Finance teams can review prior runs, compare periods, and download audit-ready Excel reports whenever needed.

The dashboard typically helps teams see:

• reconciliation name
• period
• files used
• run status
• run date and time
• who ran the reconciliation
• report access for review

That makes it easier to trace how a given Amazon marketplace reconciliation was prepared and what data was used in the run.

FAQs

What reports are usually needed for Amazon marketplace reconciliation using OMS?

Most teams use an OMS order export together with Amazon sales or invoice reports, settlement or disbursement files, return reports, reimbursement reports, and sometimes a bank statement or SKU master.

Can the same reconciliation setup be reused for future periods?

Yes. Once the mapping and matching logic are configured, the same reconciliation can be reused for future runs by changing the period and uploading the latest files.

What happens if one Amazon file is missed?

The missed file can be uploaded under the same reconciliation and the report can be refreshed so the run reflects the complete data set.

How does Cointab handle partial matches?

Partial matches are shown separately so teams can see records that are related but do not have an exact amount match. This helps isolate differences that may be caused by fees, refunds, deductions, or timing.

Can finance teams review and correct unmatched records manually?

Yes. If the system and AI cannot confidently match a transaction, users can review the open item and manually match it when the business context supports it.