Every small business eventually outgrows their accounting software, or gets fed up with it, or gets forced off it when the vendor changes pricing. The switch seems straightforward: export data from old system, import into new system, keep working. In practice, accounting migrations rank among the most stressful projects a small business undertakes.

I’ve seen this play out dozens of times working with Australian SMBs. The vendor selling the new software makes it sound easy during the demo. “We have an import wizard.” “Migration takes about a day.” “Most of our customers switch in under a week.” This is optimistic to the point of being misleading, and I wish vendors would stop saying it.

The reality is that accounting data doesn’t transfer cleanly between systems. Charts of accounts differ in structure. Tax categories don’t map one-to-one. Customer and supplier records need reformatting. Historical transactions might import but without the relationships and context that make them useful. Opening balances need to be manually verified. Bank feeds need to be reconnected and reconciled.

For a typical Australian small business moving from one cloud platform to another—say, MYOB to Xero, or QuickBooks to MYOB—the realistic timeline is 2-4 weeks of active work, not including the parallel running period where you operate both systems simultaneously to verify the new one is correct.

Parallel running is the step most businesses skip, and it’s the step that prevents disasters. Running both old and new systems for at least one full BAS reporting period (a quarter, ideally) lets you verify that the new system produces the same results as the old one. If your BAS numbers don’t match between systems, something went wrong in the migration and you need to find it before lodging.

The chart of accounts is where most migrations get messy. Every accounting system has its own default chart of accounts, and businesses customise it over time. Your old system might have account numbers that don’t align with the new system’s structure. Some accounts might need to be split, some merged, some created fresh. Doing this mapping properly takes time and accounting knowledge—it’s not just a data entry exercise.

Working with business AI specialists on a migration tooling project last year, we found that the most common error was mismatched GST classifications. An account coded as GST-free in the old system might default to GST-applicable in the new system if the mapping isn’t explicit. This error doesn’t show up immediately—it shows up when you run your BAS and the GST figures are wrong.

Payroll data is the hardest to migrate. Employee records, leave balances, year-to-date earnings, superannuation contributions—all of this needs to transfer accurately because it affects tax reporting and employee entitlements. Getting payroll wrong has legal consequences. Most accountants recommend starting the new system’s payroll at the beginning of a financial year if possible, using the old system’s figures as opening balances.

Xero has one of the better import processes for Australian businesses, but even their migration requires manual intervention for anything beyond basic contact lists and invoices. Historical bank transactions, reconciliations, and journal entries typically need manual verification.

Third-party migration services exist and are worth the cost for businesses with complex data. Companies like Jet Convert specialise in accounting software migrations and have tools that handle the edge cases the standard import wizards miss. Budget $500-2000 for a professional migration of a typical small business—it’s cheap insurance against months of messy reconciliation.

Some practical advice from watching too many migrations:

Start at the beginning of a quarter, ideally the beginning of a financial year. This minimises the amount of current-year data you need to migrate and gives clean opening balances.

Export everything before you close the old account. Most platforms let you export to CSV or PDF. Download every report, every transaction history, every contact list. Once you cancel the old subscription, accessing historical data becomes difficult or impossible.

Don’t try to migrate every historical transaction. For most businesses, migrating opening balances and the current financial year’s transactions is sufficient. Historical reports can be referenced from the old system’s exports. Trying to migrate five years of transaction history creates more problems than it solves.

Budget double the time you think you need. If the vendor says a week, plan for two. If your accountant says two weeks, plan for a month. Migration tasks expand to fill available time and then some.

Tell your accountant before you start. Your bookkeeper or accountant will have opinions about timing, chart of accounts structure, and migration approach. They’ll also need to adjust their workflow during the transition. Surprising them with a mid-year platform change is a good way to strain the relationship.

The silver lining is that most businesses come out the other side with a cleaner, better-organised accounting setup. The forced review of accounts, categories, and processes during migration often reveals years of accumulated mess that gets cleaned up in the process.