2026 guide · Self-employed
The best invoice app for the self-employed, honestly compared.
The right app depends on how often you invoice and whether you also need accounting. If invoicing is the job and you live on your phone, a WhatsApp-first tool wins. Here is the honest comparison for UK sole traders.
The honest table
Different tools, different needs.
| Tool | Best for the self-employed |
|---|---|
| WOPA | Regular invoicing from WhatsApp — create and chase without accounting overhead. |
| FreeAgent | Sole traders wanting accounting plus tax estimates. |
| Xero | Bookkeeping with accountant collaboration. |
| FreshBooks | Freelancers invoicing plus tracking time. |
| Free invoice generator | The occasional one-off invoice. |
FreeAgent and Xero are genuinely strong if you want full accounting. The gap WOPA fills is fast, valid invoicing for people who do not want to run a full accounts package just to get paid.
What to look for
Choosing when you are self-employed.
When you are a one-person business, time spent on admin is time not earning. The things that matter are: can you create a valid UK invoice quickly (ideally from your phone), will it chase late payers so you do not have to, and does it keep tidy records for your Self Assessment. WOPA covers all three from WhatsApp.
If you also want bookkeeping, expense tracking and tax estimates, weigh that honestly — an accounting package like FreeAgent does that better, and WOPA can sit in front of it as the fast invoicing layer.
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