How to Migrate to New Accounting & Invoicing Software Without Losing Data
Why Migrating Accounting Software Feels Daunting — And Why It Doesn't Have To Be
Switching accounting or invoicing software is one of the most stressful decisions a small business owner can make. The fear of losing years of financial records, breaking Making Tax Digital (MTD) compliance, or disrupting cash flow can make it tempting to stick with outdated tools long past their usefulness.
The good news is that with a clear plan and the right preparation, migration can be smooth and surprisingly straightforward. This guide walks you through the entire process, step by step, with UK-specific considerations throughout.
Step 1 — Audit Your Current Data Before You Touch Anything
Before exporting a single file, take stock of exactly what data you hold. This includes customer and supplier records, outstanding invoices, historical transactions, VAT submissions, bank reconciliation history, and any payroll records.
Log into your current software and run a full data export — most platforms allow you to export to CSV or Excel. Keep copies of your last three years of records as a minimum, since HMRC requires businesses to retain financial records for at least six years. Store these exports in a secure, backed-up location before proceeding.
Step 2 — Choose Your New Software Carefully
The UK market has several excellent options tailored to small businesses, each with different strengths. Picking the right one now saves you from migrating again in two years' time.
Xero (from £15/mo) is a strong all-rounder for diverse small businesses. It is fully MTD-compliant for VAT submissions, offers an intuitive interface, and integrates well with UK banks, making reconciliation straightforward from day one.
FreeAgent (from £19/mo) is particularly well-suited to sole traders and freelancers. It is HMRC Making Tax Digital compliant and offers strong integrations with major UK banks including NatWest and Royal Bank of Scotland, often available free if you bank with them.
Sage Accounting (from £15/mo) is another MTD-compliant option with excellent UK bank integrations, and it works especially well for trades businesses such as plumbers or hospitality operations like restaurants. If your business operates in the field, you might also consider Commusoft (from £119/mo) or Jobber (from £49/mo), both of which include invoicing built into a broader field service management platform.
Step 3 — Run Both Systems in Parallel Briefly
Never cut over to new software mid-financial-quarter without a parallel running period. Operate both your old and new systems simultaneously for at least two to four weeks — long enough to confirm your opening balances, customer records, and VAT figures all match up correctly.
This parallel period is also the right time to test your bank feed connections. UK-focused platforms like Xero and FreeAgent use Open Banking to pull in transactions automatically, so connect your accounts early and verify the feeds are pulling correctly before you rely on them entirely.
Step 4 — Migrate Data Systematically, Not All at Once
Attempting to import everything simultaneously is the most common cause of data errors during migration. Instead, follow a structured sequence to keep things manageable and auditable.
- Import your chart of accounts first — this is the foundation everything else maps to.
- Add customer and supplier contacts next, checking for duplicates carefully.
- Enter your opening balances as at a clean cut-off date, ideally the start of a VAT period.
- Import outstanding invoices and bills so your aged debtors and creditors reports remain accurate.
- Finally, bring across historical transactions only as far back as you genuinely need for day-to-day use.
Most platforms, including Xero and Sage Accounting, provide CSV import templates that map directly to their data fields. Use these templates rather than adapting your own to avoid formatting errors.
Step 5 — Verify MTD and GDPR Compliance After Migration
Once your data is in the new system, do not assume compliance is automatic. Confirm that your Making Tax Digital for VAT settings are correctly configured and that your VAT registration number, scheme (standard, flat rate, cash accounting), and filing periods all match your HMRC records exactly.
From a GDPR perspective, ensure that any customer data imported into your new platform is covered by your existing privacy notices, and check where the new provider stores data — it should be within the UK or EEA. Delete customer data from your old system once you are confident the migration is complete and the statutory retention period is satisfied.
Step 6 — Train Your Team and Set Up Integrations
Even the best software fails if your team reverts to old habits. Schedule a short training session once the migration is complete, focusing on daily workflows such as raising invoices, reconciling bank transactions, and running VAT reports.
If you take card payments, check whether your new platform integrates with your existing payment setup. Both Zettle and SumUp are popular with UK small businesses and offer integrations with several accounting platforms. Similarly, if you use e-commerce or CRM tools, rebuild those integrations on the new platform before switching off the old one.