What is the best invoicing tool for solo founders?

Every founder eventually needs to send an invoice and get paid without it becoming a part-time job. These three tools solve that at different levels of completeness — one is closer to real accounting software, one is free but simpler, one is built specifically around the freelancer workflow of proposal → contract → invoice. We compared them on which of those three shapes actually fits a solo founder, not on feature-list length.

FreshBooks — best if you want real accounting features, not just invoices

FreshBooks goes beyond sending invoices: expense tracking, time tracking tied directly to invoices, and reports detailed enough to hand to an accountant at tax time. For a founder who's outgrown "just email a PDF invoice" but doesn't need full double-entry bookkeeping software, it sits in a genuinely useful middle ground. The trade-off is cost — it's a paid tool from day one, unlike Wave.

Affiliate relationship in progress — check back for a direct link, or search "FreshBooks" directly in the meantime.

Wave — best if free actually means free

Wave's core invoicing and accounting features are free, not a time-limited trial — a genuinely rare thing in this category. For a founder just starting out who needs to send professional invoices without adding a software bill, that matters more than a longer feature list. The honest trade-off: Wave's interface feels less polished than FreshBooks, and its integration ecosystem is thinner. Payment processing itself still carries standard transaction fees, same as everywhere else — "free" means the software, not the payment rails.

Bonsai — best if you're a solo service provider, not a product business

Bonsai bundles the entire client-services workflow — proposal, contract, invoice, sometimes project tracking — into one tool, which matters specifically if you sell your time or expertise rather than a product. A consultant or freelance developer who currently juggles a separate contract template, a separate invoicing tool, and a separate proposal doc will find real value in having all three connected. It's the wrong shape if you're running a product-based SaaS business where invoicing is more transactional and less relationship-driven.

InvoiceChaser — best if the invoicing tool is fine but the follow-up isn't happening

InvoiceChaser solves a narrower, different problem than the three tools above: none of them make you actually send the follow-up when a client goes quiet. InvoiceChaser takes the invoice details and how overdue it is, and drafts the reminder email in an appropriate tone — a gentle nudge at day 3, a firmer one at day 30 — so the awkward part of getting paid doesn't depend on you remembering to sit down and write it. It's a companion to an invoicing tool, not a replacement for one; pair it with whichever of the three above you're already using.

Full disclosure: InvoiceChaser is one of ours (built by the same person behind StackIndex AI). No affiliate link, no commission — it's here because it solves a real, narrow problem the other three don't touch, not because we own it.

How we'd actually decide

• Want real accounting features (expenses, time tracking, tax-ready reports): FreshBooks.
• Just starting out, need free professional invoicing: Wave.
• Selling your time or expertise, want proposal-to-invoice in one tool: Bonsai.
• Invoicing is fine, but late payments keep slipping through: InvoiceChaser alongside whichever of the above you already use.