Access Database Migration Validation Checklist

January 12, 2026 · 8 min read

This checklist consolidates everything you need to do before, during, and after converting an Access .mdb database to .accdb. Use it as a working document: print it out, fill it in as you go, and don't sign off on the migration until every item is checked. Each section links to the detailed guides if you need more context on any item.

Phase 1: Pre-Migration Audit (Before Touching the File)

Database Assessment

Record the .mdb file size
Record the row count for every table (see Data Integrity Verification)
Record key aggregate values: total records in primary tables, current date ranges, key financial totals
Note the Access version that currently opens the .mdb (Access 2003, 2007, etc.)
Identify whether workgroup security (.mdw) is in use — if yes, plan the replacement before migrating (see Security Settings guide)
Check for a database password on the .mdb (File → Info → Encrypt with Password)

VBA Audit

Open VBA editor (Alt+F11), run Debug → Compile, fix all compile errors
Search for Declare Function / Declare Sub — add PtrSafe to each (see VBA Audit guide)
Check Tools → References — resolve any "(MISSING)" references
Search for CurrentUser() — document all uses (returns "Admin" in .accdb since user-level security was removed)
Search for early-bound Office automation (Dim xl As Excel.Application) — convert to late binding
Search for CreateWorkspace with username/password — remove or replace

SQL / Query Audit

Export all query SQL and search for unbracketed reserved words (Name, Date, Status, Level, Order, Group, Month, Year, Type, Value) — bracket them all (see Jet SQL Migration guide)
Review subqueries for ambiguous column references — add table qualifiers
Review DDL queries (CREATE TABLE, ALTER TABLE) for syntax tightness
Note any queries referencing Memo fields — they become Long Text, queries still work

Forms and ActiveX Audit

Open each form in Design View — note any controls with broken/grey placeholders
Identify the OLE Class for each ActiveX control (property sheet)
Check if MSCAL.OCX (Calendar Control) is used — replace with built-in Date Picker
Check if COMDLG32.OCX is used — replace with VBA FileDialog
Check if MSCOMCTL.OCX is used — plan to re-register updated version
See the ActiveX Controls guide for full replacement instructions

Run the pre-migration scan automatically

LegacyLeaps runs this entire pre-migration audit on your .mdb and produces a ready-to-use report — VBA issues, SQL conflicts, ActiveX controls, and all.

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Phase 2: Backup

Before Converting

Copy the .mdb to a separate archive folder (e.g., C:\Archive\DatabaseName_backup_2026-01-31.mdb)
Set the archive copy to read-only (right-click → Properties → Read-only)
Verify the archive opens correctly in Access before proceeding
Make a note of the archive location in your change log

Phase 3: Conversion

The Conversion Step

Open the .mdb in Access (the version you'll use going forward)
Go to File → Save As → Access Database (.accdb)
Save to a new location (don't overwrite the .mdb)
Watch for any error or warning messages during conversion — note them
After conversion, compact the .accdb: Database Tools → Compact and Repair Database
Record the .accdb file size (expect smaller or similar size to the .mdb)

Phase 4: Post-Migration Validation

Data Integrity Checks

Run row count comparison for every table — .accdb counts must match .mdb exactly
Spot-check 10–20 known records across key tables
Run key aggregate queries (totals, averages, counts) — compare results to .mdb
Run referential integrity queries to check for orphaned records
Verify Long Text (former Memo) fields aren't truncated in large records

Functionality Testing

Open every form in normal view — no errors on load
Test every form's add/edit/delete operations
Test every button and VBA event handler on each form
Open every report — verify correct data renders
Run every saved query — verify no SQL errors
Test any import/export routines in VBA
Test any code that creates or opens Excel, Word, or Outlook objects

Security Configuration

Add the .accdb folder to Trusted Locations on the development machine
Verify database opens without security warning bar after Trusted Location is set
If multi-user, configure Trusted Locations on all user machines (or via Group Policy)
If database password was set on .mdb, set a new password on .accdb (AES-encrypted)
If workgroup security was used, confirm the VBA login replacement is working correctly

Performance Check

Run Database Tools → Analyze Performance and review recommendations
Open the slowest reports and verify load time is acceptable
For multi-user databases, test concurrent access with multiple users

Phase 5: Deployment and Sign-Off

Going Live

Deploy .accdb to the production location
Update any shortcuts or batch files pointing to the old .mdb path
Notify users — give them a one-page summary of any UI changes (e.g., new date picker instead of calendar control)
Set a 30-day review date to evaluate whether any issues have surfaced
Keep the .mdb archive read-only and available for 30 days minimum

30-Day Sign-Off Criteria

No data loss or corruption reported
All forms and reports working correctly for all users
Performance is acceptable
No error logs attributable to the migration
.mdb archive can be moved to cold storage

For detailed guidance on any section of this checklist, see the full guides in our Complete Guide to Access Database Migration.

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