Manufacturing
Dynamics NAV and AX archives: what to keep after moving to Business Central
By SourceX Editorial · Reviewed by Noah Loul ·
Short answer
A Dynamics NAV archive should keep the detailed history a move to Business Central often leaves behind: posted ledger entries, item and value entries, production orders, lot tracing and closed documents. Re-implementations and AX moves typically carry master data, open items and balances. Keep the old database readable and documented before licenses and servers lapse.
Key takeaways
- Migrations usually bring master data, open transactions and balances; detailed posted history often stays in NAV or AX.
- Ledger and item entry tables, not saved reports, are the history worth preserving.
- A database backup is not an archive unless someone can still read it without the old application.
- Retention depends on tax, contract and product rules, so set it with your accountant and counsel before switching off.
What usually moves to Business Central and what stays behind?#
What moves to Business Central depends on the path. A NAV database upgraded technically through the supported upgrade path can carry much of its history along, while a fresh implementation, and almost every move from Dynamics AX, usually brings master data, open items and opening balances and leaves detailed posted history behind.
Partners often recommend the lighter approach for good reasons: cleaner data, a faster cutover and no legacy customizations to rebuild. The cost is that years of transaction detail now live only in the old system, and the table shows the usual split.
| Data area | Usually migrated | Usually left in the archive |
|---|---|---|
| Customers, vendors, items, BOMs, routings | Active records, cleaned | Inactive and obsolete records |
| Receivables and payables | Open invoices and credits | Closed entries and payment history |
| General ledger | Opening balances or summarized periods | Detailed G/L entries for prior years |
| Inventory | On-hand quantities and current costs | Item ledger and value entry history |
| Production | Open production orders | Finished orders, consumption, output and capacity entries |
| Lot and serial tracking | Currently tracked stock | Full trace history |
| Customizations and add-ons | Rebuilt as extensions or dropped | Custom tables and fields |
Why the history left behind still matters#
The history left behind still answers questions the business will be asked. Auditors and tax authorities can ask about prior years, customers can dispute old invoices, warranty claims need the lot and serial trail of a part built long ago, and estimators use historical costs to quote repeat work.
Retention rules differ by record type and by the laws, contracts and customers involved, so there is no single period to apply. For federal tax, the IRS says to keep records that support income, deductions or credits until the period of limitations for that return runs out, generally three years and longer in some cases. IRS Rev. Proc. 98-25 treats electronic records in a computerized accounting system as records to keep while their contents may become material to tax administration. Set the full schedule with your accountant and counsel, and keep the archive usable rather than merely stored.
Detailed history also has a newer use. Years of production orders, scrap, lot genealogy and service records are the kind of operational history AI developers license, and an archive documented at cutover is far easier to assess later.
Which NAV and AX tables hold the history worth keeping#
The history worth keeping lives in entry tables, not in reports. Reports can be rerun if the entries survive, but entries cannot be rebuilt from saved PDFs.
Two storage details trip up later readers. NAV on SQL Server keeps a separate set of tables for each company, with the company name as a prefix, and stores option fields as numbers, so a status column reads 0, 1 or 2 without its captions. AX keeps legal entities in shared tables, with most rows tagged by a DataAreaId column. Both belong in the data dictionary.
Add-on tables from ISV products, such as quality, EDI or shop floor modules, are easy to forget because they sit outside the standard schema. List them by name, with what each one stored, before the server goes away.
- NAV: G/L Entry, Cust. Ledger Entry, Vendor Ledger Entry and their detailed ledger entry tables
- NAV: Item Ledger Entry, Value Entry and Capacity Ledger Entry for inventory, cost and production history
- NAV: posted sales and purchase document headers and lines, plus comment lines
- NAV: finished production orders with components and routing lines, and item tracking entries
- NAV: Change Log Entry, if change logging was turned on
- AX: GeneralJournalAccountEntry in AX 2012 or LedgerTrans in AX 2009, plus CustTrans and VendTrans
- AX: InventTrans with InventDim for inventory movements and lot or serial history
- AX: ProdTable, ProdRoute and production journals, plus quality orders and nonconformances if used
Archive options compared#
The main archive options for NAV and AX data are a read-only legacy server, a tested database backup, an export to a reporting database, a third-party archive product and history tables inside Business Central, and each trades convenience against cost and risk. A common approach combines two: a verified backup as the record of last resort, and a readable layer that finance and operations staff can actually query.
Whichever mix you choose, check your license terms and Microsoft's lifecycle information for your NAV or AX version, since many older versions are past the end of support. Running unsupported software on a network is a security decision, not only an accounting one.
| Option | What it keeps | Main effort | Main risk |
|---|---|---|---|
| Legacy server kept read-only | Everything, in the familiar screens | Patching, licensing and hosting the old stack | Unsupported software on the network |
| Database backup in storage | Everything, in raw form | Storage and periodic restore tests | Nobody remembers how to read the schema |
| Export to a data warehouse with reports | Selected tables, easy to query | Scoping and building the exports | Tables left out by mistake |
| Third-party archive or viewer product | Ledgers and documents in readable form | Subscription and setup | Dependence on the vendor's format |
| Historical tables inside Business Central | Selected history in custom tables | Partner work and database capacity costs | Clutter and confusion with live data |
Before you switch the old system off#
Before you switch the old NAV or AX system off, prove the backup restores, document the schema and customizations, freeze key reports and name an owner for the archive. Each step is cheap while the system is running and expensive afterward.
Assign the checklist to a named person, usually the controller with IT support, and keep the evidence of each step with the archive itself.
- Take a full database backup, a SQL Server backup or a native backup on very old NAV versions, and prove it by restoring it to a separate server.
- Export a data dictionary: tables per company, fields, option captions and dimension codes.
- Document customizations and add-on tables, with what each one stored.
- Export year-end trial balances, aged receivables and inventory valuations as fixed reports.
- Record the application version and how to obtain a runtime that can open the data.
- Name an owner for the archive and write down the retention schedule.
- Note where personal data sits, such as employee and contact records, for later review or deletion.
Illustrative: a fabricator documents its NAV archive at cutover#
Illustrative: a fictional structural steel and sheet metal fabricator ran an older NAV version for many years with a shop floor add-on. Its partner moved the company to Business Central online with master data, open orders and opening balances, which kept cutover clean.
The controller insisted on one more step. The team restored the final NAV database to a separate server, exported ledger, item, value, capacity and item tracking entries to a small reporting database, and wrote a data dictionary covering the add-on tables. The old application server was then shut down.
Two outcomes followed. Warranty questions about older assemblies could be answered from the reporting database without restarting NAV. And when the company later looked at licensing operational records, the documented archive made the inventory a matter of reading the dictionary rather than reverse-engineering a database.
How SourceX looks at legacy ERP archives#
SourceX treats a system retirement as a good moment to assess records, before access disappears. The fit check needs only metadata, such as which NAV or AX version held the data, which entry tables survive and how many years they cover, and nothing is shared during the initial assessment.
Under the SourceX Enterprise Data Value Framework, a documented archive scores better on data cleanliness and lowers preparation cost, while recency and rights shape what a buyer can use. If a package proceeds, the SourceX Evidence Packet records the archive's provenance alongside licensing rights, permitted use, the privacy record and release authorization.
Frequently asked questions
Can Business Central hold our full NAV history?
Sometimes. A technical upgrade from a supported NAV version can bring history along, but it also carries old data quality problems and customizations, and database capacity in Business Central online has costs. Many companies keep full history in an archive and bring only what daily work needs.
How long do we have to keep old ERP records?
There is no single answer. Tax rules, audit needs, customer and supplier contracts, product liability exposure and industry requirements all set different periods for different records. Build a retention schedule with your accountant and counsel, and keep the archive readable for at least the longest period that applies.
Do we need to keep paying for NAV or AX licenses to read the archive?
It depends on your license terms and how you plan to read the data. Running the old application usually requires a valid license and supported infrastructure. A SQL Server copy can be read with database tools instead, but someone needs the data dictionary to make sense of it.
What about personal data in the old system?
NAV and AX databases hold employee records, contact persons and sometimes bank details. Privacy laws may apply to how long you keep them and who can access them. Identify those tables before archiving, restrict access, and plan review or deletion once retention ends.
Is a legacy ERP archive useful for AI developers?
It can be, especially when production orders, scrap, lot genealogy, purchasing exceptions and service history link together over several years. Financial ledgers alone are less useful. Rights review and privacy preparation come first, and value depends on what a buyer needs.
Sources
- The IRS says to keep records supporting an item of income, deduction or credit until the period of limitations for that return runs out: generally 3 years, 6 years if unreported income exceeds 25% of the gross income shown, 7 years for a loss from worthless securities or a bad debt deduction, and indefinitely if no return or a fraudulent return was filed. Source
- Rev. Proc. 98-25 treats machine-sensible records in a taxpayer's automatic data processing system as records under IRC 6001 that must be retained so long as their contents may become material to tax administration, at a minimum until the period of limitation for assessment, including extensions, expires for each tax year. Source
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