Updated Checked by the Tax-Services.ca editorial team How we check
The best practice for data migration in accounting is to prove that nothing changed. The CRA’s electronic record keeping circular says a conversion to a new format must not cause any loss, destruction or alteration of information, and the records you end up with must be reliable and readable. So the plan runs on evidence: what went in, what came out, and proof that the two match.
What does the CRA say about moving records to a new system?
Three things, all in the circular on electronic record keeping (IC05-1R1). First, converted records must be reliable and readable, with no information lost or altered. Second, you should document changes to your system, so a later reader can see what was done and when. Third, before you switch, confirm the audit trail for each transaction will survive and that the new system can still export the data in a commonly used, non-proprietary format.
The clock doesn’t restart. Records are kept for six years from the end of the last tax year they relate to, and that holds across any system change. If a migration drops 2021 invoices, you’ll still be asked for them.
How do you migrate accounting data without losing anything?
Work in this order. It’s dull and it works.
- Freeze the old system on a stated date and export everything: transactions, customer and supplier lists, tax codes, payroll history, attachments.
- Store that export, unchanged, somewhere you control. It is your fallback and your proof.
- Clean the data before you move it. Merge duplicate customers, fix blank tax codes and settle old open items.
- Load a copy into the new system as a test, not the real thing.
- Compare totals. If they differ, find out why before anything goes live.
- Write down what you did, with dates and the name of whoever did it.
The list of steps is short. The discipline of not skipping step 2 is the hard part, since it feels like clutter once the new system looks fine.
Consider Linda, who keeps the books for a family-run bakery in Fredericton. She exports everything on a Friday, saves a read-only copy to an external drive, and loads a test file over the weekend. On Monday she compares the closing balance sheet in both systems and finds a supplier balance that’s $38 off. It turns out to be a duplicate customer record. Had she gone live on Friday night, she’d have been chasing that for months.
What should match after the move?
Pick checks that an independent source can confirm. Here’s a reference table you can adapt.
| Check | What to compare |
|---|---|
| Trial balance | Old closing balances against new opening balances |
| Receivables and payables | Open items by customer and supplier |
| Sales tax | Tax collected and paid on the same period in both systems |
| Payroll year to date | Gross pay, tax, CPP and EI by employee |
| Attachments | A sample of invoices opens and matches the entry |
Can you recalculate the tax to test the migrated data?
Yes, and it catches more than you’d think. Suppose your Ontario sales for a period were $84,000 before tax. The GST/HST calculator shows 13% HST of $10,920, so $94,920 in all. If the migrated ledger shows something else, the tax codes didn’t come across properly. An Alberta sale would carry 5% GST, which is $4,200 on the same amount, so a mix of provinces needs a check by province.
Do the same with payroll. For an Ontario employee on $2,500 every two weeks, the payroll remittance estimate is the comparison point for remittances, though it’s an estimate and ignores benefits, so expect small differences. Large ones mean the pay history loaded wrongly.
What goes wrong with data migration?
Opening balances are the classic trap: they match the total and hide errors in the detail. Compare by customer as well as in total. Date formats are next, because 03/04 means different months to different systems. Then there’s the attachment problem. Invoices and receipts stored as images in the old product often don’t travel with the export, and you find out a year later.
A smaller but real one: people migrate mid-year. It’s often simpler to cut over at a year end or a filing-period end, so each return comes from one system. If you can’t wait, keep both and label clearly where the split falls.
Do you need to keep the old system running? Not always. The CRA circular says the equipment and software needed to read records must be available for the retention period, or the data must be in a form that doesn’t need them. A plain export in an open format solves that, which is why step 2 matters. The circular also says a records copy is expected to be kept at your place of business or home in Canada, unless the CRA gives permission otherwise.
We haven’t judged any migration service or product, and we couldn’t verify vendor claims. Once you’re live, the ROI calculator can test whether the move paid off.
What should you do in the first month after cutover?
Treat it as a probation period. Reconcile the bank account by hand at the end of week one, not just at month end. Run the first sales tax report from the new system and compare it with a quick manual tally. Keep the frozen export from step 2 untouched, and don’t cancel the old subscription until a full filing cycle has run cleanly on the new books. If something looks off, write it down with the date, because that note is part of your record of what changed. Most migration problems show up in the first thirty days, which is why that month is worth the extra care.
The sources behind this page
Conversion, audit trail, format and retention points come from CRA Information Circular IC05-1R1 and the CRA page on where to keep records. The tax figures come from our calculators using 2026 rates. No government body has reviewed or endorsed what you read here.
Frequently asked questions
What does the CRA say about converting records?
Converted records must be reliable and readable, and the conversion must not lose, destroy or alter information. Changes to the system should be documented.
Do I still keep records for six years after switching software?
Yes. The six years run from the end of the last tax year the records relate to, whatever system holds them.
Do I have to keep the old accounting system?
Not if the data is stored in a form you can still read and export. The circular asks that the equipment and software needed to read records stay available, or that the records don't depend on them.
When is the best time to migrate?
A year end or filing-period end is simpler, so each return comes from one system. Mid-year works if you record where the split falls.
How can I check migrated sales tax?
Recompute tax on a period's sales, for example 13% HST on $84,000 of Ontario sales is $10,920, and compare it with the new ledger.
All family and benefits calculators
- Self-employed taxes in Canada: income, CPP and GST
How tax works when you are self-employed in Canada: reporting income and expenses, paying both halves of CPP, instalments and when to register for GST