Sole trader invoice app: SaidToPaid, FreeAgent, QuickBooks and Xero compared

*Published by SaidToPaid, written by its founder. Provider information checked from public sources on 12 October 2026. This is a feature checklist, not a hands-on review or a score. Not confirmed means we could not verify it in public information; it is not a claim the feature is missing.*

Short answer: FreeAgent, QuickBooks and Xero are accounting apps that also do invoices, useful at tax time. SaidToPaid is a simple invoice app for sole traders who work away from a desk and want invoices out and paid quickly.

SaidToPaid lets you speak or type what you did, turns it into a priced invoice draft, and only sends it once you have checked and approved it. You can try it with 5 real documents free, no card needed. Solo is £10 + VAT a month on the founding rate (100 documents a month, one user) and Pro is £20 + VAT a month on the founding rate (unlimited documents, up to three users).

Sole trader invoice app checklist

Which one fits

If you want your tax return and bookkeeping handled, choose an accounting app. If invoices are the part that eats your evenings, SaidToPaid handles that and you can export for your accountant.

Compare all the main options in best invoice app in the UK, or read how to choose an invoice app.

Frequently asked questions

What is the best invoice app for a sole trader in the UK?

It depends on whether you want accounting too. For quick invoices made on your phone by voice, SaidToPaid. For bookkeeping and tax returns, FreeAgent, QuickBooks or Xero.

How much does a sole trader invoice app cost?

SaidToPaid is free for 5 documents, then £10 + VAT a month on the founding Solo rate for 100 documents a month.

What must a sole trader put on an invoice?

Your name and any business name, an address, the customer's name and address, a unique invoice number, the date, what you did and the amount due. Add your VAT number if registered.