Does it connect to Xero, QuickBooks, Sage or other accounting software?

On the Growth plan and above you can connect Xero, QuickBooks Online, Sage Accounting or FreeAgent (one at a time) in Settings > Accounting: issued invoices, payments, refunds, clients, suppliers, bills, bill payments and receipts are then sent to your accounting package as they happen (one way only; nothing is read back except your accounts and VAT codes). QuickBooks keeps Sales Base's invoice numbers only if Custom transaction numbers is switched on in QuickBooks. You choose the sales account, the account each kind of payment goes into, the VAT codes, an account for each purchase category and the date to start from; anything the package refuses is listed with the reason and a Retry button. Sage keeps its own invoice numbers, so Sales Base's number goes in the invoice's reference. For Sage 50, Export for accounts gives you four plain CSV files for any period (sales invoices, invoice lines, payments and clients), with net, VAT and gross in separate columns, which your bookkeeper can open in a spreadsheet or import into software that accepts CSV. Connected services are Stripe, PayPal and GoCardless for payments, and Outlook or Microsoft 365 for email on the Scale plan.