Ask your accountant first — genuinely
This is the one software category where the opinion of the person who files your return should outweigh a feature comparison. An accountant fluent in your platform catches errors faster, charges less for cleanup, and can work in your file directly. If your bookkeeper is a Xero specialist, the correct answer is usually Xero regardless of what a scorecard says.
Count the users you will actually need
Xero includes unlimited users on every plan. QuickBooks Online charges by tier and caps them — a fact that quietly reverses the price comparison once a bookkeeper, an office manager and a partner all need access. For a single-owner business the caps are irrelevant; past three people they can dominate the total cost.
Watch the promotional pricing cliff
Discounting is heavier here than anywhere else in SaaS: 50–90% off for three to six months is normal. Those offers are real, but the renewal is what you are actually buying. Compare list prices, then treat the discount as a one-off bonus rather than the price.
Payroll and payments are separate purchases
Almost every headline price excludes payroll, and payment processing carries per-transaction fees on top. If you need to run payroll, price the bundle — or price a dedicated payroll product like Gusto alongside — before deciding. A cheaper ledger with expensive payroll is not a saving.