You've decided that historical data migration matters. You understand why keeping your transaction history accessible in your new ERP system is valuable for forecasting, customer service, and audits. Now comes the practical question: What exactly should you bring over?
The answer isn't "everything." Migrating every record from your legacy system would be time-consuming and, in many cases, unnecessary. But migrating too little leaves gaps you'll regret later when someone asks a question your new system can't answer.
Fortunately, having a clear framework for what to migrate and why makes the process faster and less stressful. In this article, we'll walk through each document type that Stellar One recommends for historical data migration, explain when each one matters, and help you understand what belongs in your migration plan.
The Seven Categories of Historical Data to Migrate Into Your ERP Platform
At Stellar One, we've identified seven categories of historical data that cover the majority of business needs. Not every company needs all seven, but understanding what each one offers will help you make informed decisions about scope.
1. Historical Invoices (AR)
Invoices are the most valuable category for most businesses. They tell you what you sold, to whom, at what price, and when. This information is the foundation for sales trend analysis, customer service lookups, and revenue forecasting.
What makes invoice data particularly useful is that it's captured at the line level. This means you're not just seeing that a customer received an invoice for $5,000. You're seeing exactly what was on that invoice: which inventory items, what quantities, and what amounts. That granularity is what makes historical data actually useful for analysis.
When a customer calls and says they bought something two years ago, your team needs the ability to verify that in seconds, not days. And when you're building next year's forecast, you want actual sales data across multiple years. Invoices make both possible.
2. Historical Credits
Credits are easy to overlook, but skipping them will distort your picture of profitability. If you don't pull the credits, you’ll see only the revenue side of it.
Here's why that matters. Say you sold 1,000 units of a product last year. That sounds like strong performance, until you realize 300 of those units were returned. Without credit data, you'd overestimate demand and underestimate the margin issues with that product line.
Migrating credits alongside invoices will give you the full picture: actual revenue, return rates, and true profit margins by product, customer, or time period.
3. Historical Sales Orders
Sales orders capture what customers requested before fulfillment. For many businesses, invoices are sufficient since they represent what actually shipped and was billed. But some companies rely heavily on sales orders for planning.
Certain seasonal businesses are a good example. A company selling holiday decorations might create sales orders months before the selling season to forecast demand and coordinate overseas purchasing. Those sales orders drive planning decisions long before any invoice exists.
If your sales orders are primarily a step on the way to an invoice, you can probably skip them. If they drive forecasting or represent commitments you need to track historically, include them.
4. Historical Purchase Orders
Purchase orders document what you ordered from vendors, when, and at what agreed-upon price. Similar to sales orders, the question is whether POs provide information beyond what's captured in your AP invoices (bills).
If you use purchase orders for vendor management, tracking what was ordered versus received, or analyzing lead times, they're worth migrating. If they're transactional documents that simply lead to a bill, the bills themselves may be sufficient.
5. Historical Bills (AP Invoices)
Bills, your accounts payable invoices, show what you purchased, from which vendors, and at what cost. This history is valuable for tracking supplier pricing over time, identifying purchasing patterns, and answering audit questions about past expenses.
If you've bought the same product from multiple suppliers over the years, AP history will let you compare who gave you the best pricing and whether costs have been trending up or down. It's also essential for any serious spend analysis.
6. Historical Batch and Serial Numbers
If you're in a regulated industry, like food, pharmaceuticals, medical devices, or automotive parts, lot and serial number tracking isn't optional. You may need to trace a specific batch back through your supply chain years after production.
Imagine a product recall for something you manufactured three years ago. With historical batch and serial data in your ERP platform, you can identify affected lots, trace them to specific customers, and respond quickly. Without it, you're digging through archived files or hoping your old system still runs.
For businesses outside regulated industries, this category is often unnecessary. But if traceability matters to your operations, it belongs in your migration plan.
7. Historical GL Transactions
Your general ledger contains the detailed transactions behind your financial statements. For most businesses, migrating three years of trial balances provides enough data for comparative financial reporting.
But there are cases where GL transaction detail is valuable. If your finance team regularly needs to investigate anomalies, such as major differences found during the financial close process, having the underlying transactions will let them drill in without hunting through old systems.
The question to ask: How often does someone need to see the individual postings behind a historical balance? If the answer is "rarely," trial balances are probably sufficient. If it's "monthly," consider migrating the details.
Why Printed Forms Matter With Your ERP Solution
There's one capability that often gets overlooked when planning a migration: the ability to reprint historical documents.
Your customer's customer doesn't know or care that you switched ERP systems. They shouldn't have to. So when someone calls and asks you to resend an invoice from two years ago, you need to be able to do that without logging into a legacy system that may or may not still work.
When historical data is properly migrated, you can generate well-formatted business documents, like invoices, purchase orders, and bills, as PDFs directly from your new ERP solution. That's not just a convenience. It's the kind of seamless customer experience that builds trust and avoids awkward conversations about why you can't access your own records.
How Far Back Should You Go in Migrating Historical Data to Your ERP Platform?
The most common timeframe we see is three to five years of history. This span provides enough data for meaningful trend analysis and covers most operational questions.
For audit and compliance purposes, seven years is often the benchmark. The IRS recommends keeping certain business records for at least seven years, and many accountants advise using seven years as a safe default. Some industries have even longer requirements.
But here's the practical answer in question form: How far back do you have usable data? If your legacy system has 10 years of usable records and you want them accessible, as long as your ERP solution can accommodate your historical data, there's no technical reason you can't migrate all of it. The constraint is usually effort and time, not capability.
The AI Advantage of Historical Data in an ERP Solution
One consideration that's becoming increasingly relevant: AI-powered tools work better with more data.
Modern ERP systems like Acumatica are building AI capabilities, like product recommendations, demand forecasting, and anomaly detection. These capabilities rely on historical transaction data. If you migrate with only a few months of test transactions, those tools will have nothing meaningful to analyze.
If you bring over years of invoices, on the other hand, you can use AI-driven features from day one. Product recommendations based on what customers actually bought together. Trend analysis across real historical patterns. The more data you migrate, the more value these tools can deliver immediately.
Questions to Ask Before Finalizing Your ERP Implementation Scope
Before you lock in your migration plan, work through these questions with your team:
- What historical lookups does our sales or customer service team perform most often?
- What data do we use to build forecasts and budgets?
- What records would an auditor ask for, and how far back?
- Do we have regulatory or traceability requirements for lot and serial numbers?
- How often does finance need to drill into GL detail from prior years?
- Do customers ever ask us to resend old invoices or order confirmations?
The answers will point you toward the documents and timeframes that matter for your business.
Your Next Steps in Migrating Historical Data to Your ERP System
Deciding what to migrate is only part of the equation. You also need to think about how that data will be stored and accessed once it's in your new system.
Your next step is understanding the different approaches to storing historical data, and why some methods will leave you with records you technically have but can't practically use. Read "Storing Historical Data: ERP Integration vs. Alternative Methods" (coming soon) to compare your options.
At Stellar One, we help members define the right migration scope based on how they actually run their business. If you're planning an ERP transition and want help deciding what historical data to prioritize, we'd be happy to work through it with you. Click below to start your free Acumatica deployment.
Frequently Asked Questions About What Historical Data to Migrate Into an ERP System