1. Pick a cut-off day
Choose the day the old till stops taking account sales, ideally straight after you've sent month-end statements. Every account sale before it stays in the old system; every sale after it goes through Shopify.
Keep the old system running, read only, for a couple of months to look things up and take payments against old invoices.
2. Get your balances out of the old till
You need two things from the old till: the customer list, and what each customer owes, ideally invoice by invoice rather than one total. Invoice by invoice keeps the ageing right, so you still know what's 60 days late after the move.
Lightspeed Retail (X-Series)
- Customers: Customers, then Export list, gives a CSV. Big lists over 1,000 customers have their own export steps.
- Balances: each customer's Account tab shows their on-account balance and history. Lightspeed doesn't document a report of every balance at once, so print the balances or ask Lightspeed support for an export before you cancel.
Lightspeed Retail (R-Series)
- Customers: Customers, then Export, gives a CSV.
- Balances: the Credit Accounts page under Customers lists everyone with an account, with outstanding and overdue amounts. Print or email each customer's account statement as your record of open invoices.
Epos Now
- Balances: each customer's Current Balance is on their record in Customer Management. Epos Now's customer reports can be exported to Excel.
- Epos Now doesn't document a customer CSV export or a single balance report, so ask their support team which report lists every customer's credit balance.
Square
- Customers: the Customer directory has an Import/Export option.
- Balances: House accounts, then Overview, shows each account. House accounts, then Reports, exports a CSV of transactions, not balances, so note each account's balance from the Overview too.
Menus change. These steps come from each company's help centre in October 2026.
3. Set up your account customers in Shopify
In Shopify, each trade customer becomes a company with its locations, buyers and payment terms. B2B is available on the Basic, Grow, Advanced and Plus plans.
- A few dozen accounts: add them by hand in Shopify admin, under Customers then Companies. It's the best moment to tidy up names and addresses.
- Hundreds of accounts: Shopify has no built-in spreadsheet import for companies. Its help centre suggests the Matrixify app.
- Set payment terms on every company, matching what the customer agreed to with you.
4. Bring over what each one owes
Shopify doesn't have a place for balances owed from before you joined it. You have three choices:
- A spreadsheet of old invoices that you tick off as customers pay. It works, but staff at the till can't see it.
- Draft orders for each old invoice. That adds fake orders to your sales reports, so we don't recommend it.
- An app that holds carried-over balances, so they count towards each customer's credit limit and appear on their statement.
Whichever you choose, use one line per unpaid invoice: company, invoice number, invoice date, due date and amount.
5. Check the totals, then tell your customers
- Add up what you've brought over and compare it with the old till's total owed on the cut-off day. They should match to the penny.
- Send every account customer a statement from the new system with a short note: “We've changed our till. Here's your account as of [date]. Please tell us if anything looks wrong.” Customers spot mistakes fast.
6. Day one at the counter
- Show staff how to find a trade customer and charge a sale to their account.
- Agree what happens when a customer is over their limit. Our credit policy template sets out the rules.
- Make sure everyone knows payments against old invoices are recorded in the new system, so balances stay right.
- Keep the old till's final balance report somewhere safe.
This guide is based on each company's help centre in October 2026: Lightspeed X-Series, Lightspeed R-Series, Epos Now, Square and Shopify. Lightspeed, Epos Now and Square are trademarks of their owners; we're not affiliated with them.