S/4HANA Finance Data Migration: Reconcile Before and After

In an ECC to S/4HANA system conversion, you reconcile finance data twice. Before the conversion, you run SAP's FIN_CORR family of reports in ECC production to find and fix inconsistencies. After SUM, you run the finance data migration in FINS_MIG_STATUS and compare the migrated Universal Journal against a "before" snapshot you took at period close. The controller signs off on that comparison, plus a short, documented list of any errors you accepted. Not on a green traffic light.

This guide covers one slice of the conversion: getting ledger, asset and inventory values into ACDOCA with numbers you can defend. For the full journey, see our end-to-end ECC to S/4HANA migration guide.

Why finance gets its own migration step

Most of a system conversion happens inside the Software Update Manager. Finance is the exception. SUM creates the new tables, including the Universal Journal table ACDOCA, but leaves them empty. You then run the finance data migration from the IMG, one client at a time. There is no standard option to leave a company code out: SAP Community (SAP) notes that in a standard conversion all company codes must be migrated.

Three things raise the stakes:

• Asset Accounting is frozen until you finish. SAP Help says it plainly:

  "As soon as you have installed SAP S/4HANA, you can no longer post in Asset Accounting."

  Postings start again only after the migration is fully complete, so a complete period-end close before installation is a prerequisite (SAP Help Portal).
• The Material Ledger is switched on even if you never used it. The conversion activates it for inventory valuation (SAPinsider). Unfinished costing runs make the ML migration step M10 in FINS_MIG_STATUS run longer (SAP Community).
• It runs inside production downtime. Every hour of migration and fixing comes out of your cutover window.

The governing document is SAP Note 2332030 (Conversion of accounting to SAP S/4HANA). The current conversion guides still point you to it for both preparation and finance data migration (SAP Conversion Guide, Private Edition 2025).

The reconciliation flow at a glance

1. AssessReadiness Check Financial Data Quality and the SI-Check finance pre-checks
2. Detect in ECCFIN_CORR_RECONCILE, FIN_AA_CORR_RECON and FIN_ML_CORR_RECONCILE in production
3. Correct at sourceFIN_CORR_MONITOR, correction notes, SAP incidents
4. Close and snapshotPeriod-end close, carry-forward, "before" reports frozen
5. MigrateSUM, then FINS_MIG_STATUS run per client
6. Compare and sign"After" reports against the snapshot, accepted-error log, controller sign-off

Tool	Runs in	What it tells you	Evidence to keep
SI-Check finance pre-checks	ECC	Whether ledger, company code and controlling area settings allow a migration; errors explained in SAP Note 2245333	Check log at each run
FIN_CORR_RECONCILE / FIN_CORR_DISPLAY	ECC	General Ledger inconsistencies, using checks ported from the S/4HANA migration (SAP Note 2755360)	Issue list by company code and fiscal year
FIN_CORR_MONITOR	ECC	Analyzes the last reconciliation run and corrects some error types (SAP Note 2956096)	Simulation and correction logs
FIN_AA_CORR_RECON / FIN_AA_CORR_DISPLAY	ECC	Asset Accounting preconditions (SAP Note 2896400)	Issue list, fix owner
FIN_ML_CORR_RECONCILE / FIN_ML_CORR_DISPLAY_ISSUE	ECC	Material Ledger inconsistencies; detection only, no self-correction	Issue list, notes applied
FINS_MIG_STATUS	S/4HANA	Runs and monitors each migration activity; red status stops the chain	Run logs, error overview, resets

Compiled from SAP sources listed below. Check current note versions before implementing.

Step 1: Find inconsistencies in ECC production, early

Start in the SAP Readiness Check. Its Financial Data Quality section shows General Ledger and Fixed Assets inconsistencies from your production system and helps estimate the cleanup effort (SAP Community (SAP)). In parallel, the simplification item check (report /SDF/RC_START_CHECK) runs the finance configuration pre-checks. Our guide to SI-Check return codes 7, 8 and 12 covers what to do when they fail.

Then go deeper with the transactional checks:

1. General Ledger. Implement SAP Note 2755360 to get FIN_CORR_RECONCILE. These checks match the ones S/4HANA runs before the finance data migration. Results are written to table FIN_CORR_ISSUE and displayed in FIN_CORR_DISPLAY (SAP Community (SAP)). Classic GL and New GL are both supported (SAP Community (SAP)).
2. Asset Accounting. Implement SAP Note 2896400 for FIN_AA_CORR_RECON and FIN_AA_CORR_DISPLAY (SAP Community (SAP)). Keep running the GL-to-AA reports your team already uses, RAABST02 and RAABST01, for leading and parallel valuation (ERPfixers).
3. Material Ledger. FIN_ML_CORR_RECONCILE and FIN_ML_CORR_DISPLAY_ISSUE detect ML problems but cannot correct them. Fixes come through correction notes or SAP Support (SAP Community (SAP)).

Step 2: Correct at the source, and keep the trail

FIN_CORR_MONITOR reads the last FIN_CORR_RECONCILE run and fixes certain error classes. You switch on correction mode, select a line, simulate, then correct. The list of correctable errors is in SAP Note 2956096 (SAP Community (SAP)). The rest needs manual fixes, notes or an SAP incident.

From a sign-off point of view, these are changes to production financial data. Log each correction run with the note, the company code, fiscal year, number of documents affected, who ran it and who approved it. Auditors will ask, and the controller needs to know which numbers were already corrected.

Step 3: Close the period and freeze the "before" snapshot

Close the books fully before the technical conversion: depreciation posted, balances carried forward in every ledger and subledger to the current fiscal year, and periods locked. Then extract the reports you will compare against. A practical "before" set:

• Trial balance per company code, ledger and currency type (local, group, any parallel currencies)
• Customer and vendor open items and balances, matched to reconciliation accounts
• Asset history sheet per depreciation area, with GL account balances
• Inventory value per valuation area and the GL inventory accounts
• CO totals for the cost objects you report on (cost centers, profit centers, internal orders)
• Record counts for the key document tables, to compare against migrated line items

Store them read-only with the extraction time. Our Data Migration Reconciliation Checklist gives you a structure for the comparisons.

Step 4: Run FINS_MIG_STATUS and work the errors

FINS_MIG_STATUS (Start and Monitor Data Migration, also reached through the IMG path Conversion of Accounting to SAP S/4HANA > Data Migration) runs the migration activities in a fixed sequence because of the dependencies between them. When an activity turns red, the chain stops and later activities do not run (SAP Community (SAP)). The monitor lets you repeat check activities, reschedule, and reset steps (SAP Community (SAP)).

To analyze an error, drill from the activity to the error count, open the error overview, and write down the message number. Then look it up in KBA 2714344, SAP's list of the most frequent finance migration messages. The KBA expects you to see these first in your test conversion and resolve them before the next iteration (SAP Support). There are close to 1,000 message numbers across classes such as FINS_RECON, FINS_FI_MIG and FINS_ML_MIG. Most projects run into only a handful, and several messages often share one root cause (SAP Community (SAP)). Group errors by root cause before assigning them.

Step 5: Accept with care, then prove the "after"

Some FINS_RECON errors can be accepted. SAP Note 2643232 explains how and when (SAP Community (SAP)). Accepting an error is a business decision, not a technical one. Every accepted error needs a value impact, a reason, and a named finance approver before the production run.

Once the migration completes, rerun the "before" reports in S/4HANA and compare line by line. After migration, GL, CO, asset and Material Ledger actuals all live in ACDOCA, so a difference in one area usually shows up in another. Explain every difference, even small ones: an accepted error, a currency rounding, or an ECC correction made after the snapshot.

Rehearse it in every mock conversion

Fixes have to be made in ECC, not in the converted test system. SAP's guidance is that to be sure an error is solved in the next run, you need a new copy of production to convert (SAP Community (SAP)). Plan your mock cycles on that basis, and track three numbers from one mock to the next:

• Error count by message number. It should trend toward zero, or toward a stable, approved accepted-error list.
• Runtime per FINS_MIG_STATUS activity. This feeds the downtime estimate in your cutover runbook. Watch the ML steps closely.
• Unexplained differences. The target for the final dress rehearsal is zero.

Record these in a mock cutover rehearsal tracker. Then hand the converted system to the finance testers for period-end close, asset and inventory scenarios, as described in our phase-by-phase migration testing plan. Reconciliation proves the numbers moved; testing proves the business can keep posting on them.

Frequently asked questions

What is FIN_CORR_RECONCILE used for?

FIN_CORR_RECONCILE runs S/4HANA migration checks against General Ledger data while you are still in ECC. You get it by implementing SAP Note 2755360. Results go to table FIN_CORR_ISSUE and you review them in FIN_CORR_DISPLAY. Run it in production early, so you can fix inconsistencies before the first test conversion instead of finding them in FINS_MIG_STATUS.

Can we exclude a company code from the finance data migration?

Not in a standard system conversion. All company codes in a client must be migrated. If a company code is dormant or full of bad history, you deal with that before conversion (cleanup, archiving where allowed), or you look at a selective data transition instead of a plain conversion.

Can we go live with FINS_RECON errors?

Sometimes. SAP Note 2643232 describes accepting FINS_RECON errors. Treat each one as a documented finance decision: record the value impact, the reason and a named approver, and reconcile it explicitly in the before/after comparison. Never accept an error just because it blocks the schedule.

Do these checks apply to a selective data transition?

Yes, for the most part. SAP's finance guidance for selective data transition says the Note 2332030 activities still apply. It also says the Note 2755360 reconciliation reports should be a prerequisite for any selective data transition project (SAP Community (SAP)).

Sources

1. Conversion Guide for SAP S/4HANA Cloud Private Edition 2025, SAP SE (SAP Help Portal), 2025
2. Migrating from Classic to New Asset Accounting, SAP SE (SAP Help Portal), accessed October 2026
3. Conversion to SAP S/4HANA: Insights into Finance Data Migration, SAP Community (blog by SAP)
4. Conversion to SAP S/4HANA: Consistency checks in Finance, SAP Community (blog by SAP), originally August 2018, updated
5. S/4HANA System Conversion: Finance Data Consistency checks, SAP Community (blog by SAP), September 2020
6. Finance Consistency Checks: FIN_CORR_MONITOR, SAP Community (blog by SAP), October 2020
7. Fixed Assets Consistency Checks: FIN_AA_CORR_RECON and FIN_AA_CORR_DISPLAY, SAP Community (blog by SAP)
8. Material Ledger Consistency Checks: FIN_ML_CORR_RECONCILE, SAP Community (blog by SAP)
9. Readiness Check: Financial Data Quality Check, SAP Community (blog by SAP)
10. System Conversion to SAP S/4HANA Cloud Private Edition: How to find Finance inconsistencies?, SAP Community (blog by SAP)
11. Migration Monitor (FINS_MIG_STATUS): Resetting migration steps when encountering errors, SAP Community (blog by SAP)
12. Migration Monitor (FINS_MIG_STATUS): How to analyze errors, SAP Community (blog by SAP)
13. Conversion to SAP S/4HANA: How to handle errors during finance data migration, SAP Community (blog by SAP), 2019
14. KBA 2714344: Financial data migration to SAP S/4HANA, most frequent error messages, SAP Support
15. Financial tips on System Conversion to SAP S/4HANA projects: Prepare Material Ledger, SAP Community (blog by SAP), February 2021
16. Selective Data Transition approach for simple SAP S/4HANA projects: a Finance perspective, SAP Community (blog by SAP)
17. SAP S/4HANA 1610 Material Ledger Actual Costing: Impact on Conversion, SAPinsider
18. What to expect when migrating finance from SAP ECC to SAP S/4HANA, ERPfixers, December 2019