In this guide · 8 sections
Short answer
Pick a conversion date at the start of a month or GST period, import contacts, items and open invoices and bills, and enter opening balances from your accountant's trial balance. IRAS says you need not migrate old transactions, but must keep them retrievable for at least 5 years.
What IRAS says when you change accounting software
The most common worry is that every past transaction must be moved. It does not. IRAS's record keeping page says that when you change accounting software you do not need to migrate old transactions, but you must:
- Retain the accounting transactions in your old software for at least 5 years from the Year of Assessment or the end of the GST accounting period.
- Retain all business documents associated with the accounting records, such as source documents, schedules and bank statements.
- Be able to retrieve records when IRAS asks for them.
IRAS also accepts electronic records without prior approval, provided you follow its record keeping guides. Our guide to keeping business records for 5 years digitally covers scanning, storage and backups.
Choose a conversion date
Xero describes the conversion date as the day you start recording transactions in the new system, which may differ from the day you sign up (Convert to Xero, Xero Central). QuickBooks Online and Zoho Books use the same idea under different names.
| Option | Good for | Trade-off |
|---|---|---|
| Start of a financial year | Cleanest reports; prior year stays in the old file | You may wait months, or need year-end figures first |
| Start of a GST quarter | GST returns come from one system per period | Mid-year comparisons need both systems |
| Start of any month | Fastest switch | Year-to-date figures must be entered as balances |
Agree the date with your accountant. They will produce the trial balance as at the day before it, which becomes your opening balances. Avoid switching in the middle of a GST period: you would have to combine two systems to prepare one return.
What to move and what to leave behind
A clean migration brings across only what you need to keep trading.
| Data | Move it? | How |
|---|---|---|
| Customers and suppliers | Yes | Export to CSV, clean duplicates, import |
| Products and services | Yes | CSV import with codes, prices and tax rates |
| Chart of accounts | Yes, simplified | Map old accounts to the new chart with your accountant |
| Unpaid sales invoices and bills | Yes | Enter or import, dated before the conversion date |
| Opening balances | Yes | From the trial balance at the day before conversion |
| Fixed asset register | Usually | Re-enter assets with cost and accumulated depreciation |
| Paid invoices and old transactions | No | Stay in the old file and exports |
| Payroll history | Check | Payroll is often a separate system; keep year-to-date figures for IR8A |
The totals of your imported open invoices and bills should match the receivables and payables lines in the opening trial balance. If they do not, fix it before you go live. Our Excel to Xero migration guide shows the CSV templates and checks in detail.
Some accounting firms use paid conversion tools. Xero, for example, offers a Conversion Toolbox for its partners and lists migration partners for certain source systems on Xero Central. These can bring over more history, at a cost.
The migration plan, step by step
This is the order that avoids most problems. Allow two to four weeks for a small business.
Choose the new software with your accountant
Xero, QuickBooks Online or Zoho Books. Check GST settings, InvoiceNow support, bank feeds for your bank and which plan you need.
Agree the conversion date and get the trial balance
Your accountant prepares a trial balance at the day before the conversion date and a list of open invoices and bills.
Clean and export master data
Merge duplicate customers, remove suppliers you no longer use and export contacts and items to CSV.
Set up the cloud file and import
Configure organisation details, tax rates and the chart of accounts, then import contacts, items, open items and opening balances.
Connect bank feeds and integrations
Link your business bank accounts and any payment gateway or online store so transactions flow in automatically.
Run a short parallel period
For two to four weeks, record key transactions in both systems or compare totals weekly, then stop entering in the old one.
Archive the old system
Export reports to PDF and CSV, back up the data file to two locations, and record how to open it.
Keep the old desktop file readable for five years
The five-year rule is easy to break by accident: a PC is replaced, the program is uninstalled, and nobody can open the file when IRAS writes. Archive in more than one form.
Archive checklist
Train staff and set user access
Cloud accounting changes daily habits more than the software itself. People reconcile bank feeds instead of typing statements, send invoices from the app, and approve bills online.
- Give each person their own login with the lowest role they need; never share one admin login.
- Turn on two-factor authentication for every user, including your accountant.
- Run a one-hour session on the three daily jobs: bank reconciliation, invoicing and bills.
- Write a one-page "how we do it here" note: invoice numbering, who approves bills, when reconciliation happens.
- Remove access for leavers on their last day.
If you bank with DBS, OCBC or UOB, set up direct bank feeds early so staff learn on real data. Our guide to Xero bank feeds for DBS, OCBC and UOB explains each bank's steps.
Do it yourself or get help?
A sole proprietor with a few dozen customers can usually migrate in a weekend with the accountant's trial balance. With hundreds of contacts, multiple currencies, stock or several staff, outside help reduces the chance of wrong opening balances that take months to unpick.
IT Sorted is a Singapore-based team of developers with over 10 years of experience. Our Accounting Migration (from S$690) brings across up to 500 customers, suppliers and products and up to 200 open invoices and bills, enters opening balances from your accountant's trial balance, checks totals against the old system and keeps the old system read-only until you confirm. If the cloud software is not set up yet, add Accounting Software Setup (S$490). Your accountant keeps the books; we set up the software.
Frequently asked questions
No. IRAS says you do not need to migrate old transactions when you change accounting software. You must keep them in the old software for at least five years from the Year of Assessment or the end of the GST accounting period, keep related documents, and be able to retrieve the records if IRAS asks.
The conversion date is the day you start recording transactions in the new system. Everything before it stays in the old software, and the new system starts from opening balances taken from a trial balance at the day before. Choosing the start of a month, GST quarter or financial year keeps reporting simpler.
For a small business, plan two to four weeks. That covers choosing the date with your accountant, cleaning and importing data, connecting bank feeds and running a short parallel period. The import itself can take a day. Waiting for the accountant's trial balance is often the longest step, so request it early.
Only after you are sure you can still read the old data for five years. Some desktop programs stop opening files once a subscription lapses. Before cancelling, export ledgers, reports and transaction lists to PDF and CSV, back up the data file in two places, and confirm the file opens in read-only mode.
Xero, QuickBooks Online and Zoho Books are all used by Singapore SMEs. The right choice depends on your accountant's preference, bank feed support for your bank, GST and InvoiceNow needs, multi-currency and stock requirements, and price. Ask your accountant first, because they will work in the file every year.