kalkül alternative

Billy vs. kalkül: is paying worth it against a free tool?

kalkül is an Austrian invoicing tool from Linz whose core features are permanently free — a fair starting point for a one-person business that just needs BAO-compliant invoices. Worth knowing for context: kalkül advertises no AI features on its site, and reminders are sent manually.

That is exactly where Billy starts: the AI assistant creates invoices from one sentence, watches open items and sends payment reminders automatically. Billy also covers Austria AND Germany in one account — kalkül states an explicit focus on Austria alone.

Why freelancers move from kalkül to Billy

A free tool gives you a form. Billy gives you an assistant — and it keeps working after the invoice has gone out.

  • An invoice from one sentence instead of filling in a form — kalkül has no AI features
  • Automatic dunning: the assistant sends reminders itself; in kalkül you click every reminder manually
  • Recurring invoices in one sentence — not advertised by kalkül
  • Austria and Germany compliant in the same account (§11 öUStG / §14 UStG)
  • Colors, fonts and layout from the first plan — in kalkül those are for paying supporters only

Billy vs. kalkül at a glance

Comparison of Billy and kalkül
Billykalkül
AI & automation
Create an invoice from an AI promptYescore featureNono AI features on the vendor site
Automatic dunningYesfrom the entry planNoreminders are sent manually
Design & interface
Live preview while typingYesPartiallylive preview in the design editor, not the invoice form
Custom brandingYeslogo, colors, layoutPartiallylogo free; colors & layout for paying supporters only
Invoicing workflow
E-invoicing (XRechnung/ZUGFeRD/ebInterface)NoPDF invoicesNonot offered
Countries, bookkeeping & price
AustriaYes§11 öUStG preconfiguredYesBAO-compliant, small business
Germany (§14 UStG)Yessame accountNovendor states an explicit Austria focus
Pricefrom €9 / month, 7-day free trialcore features permanently free; supporter subscription price not public

kalkül pricing and feature claims per the vendor, verified on July 31, 2026. Prices net; subject to change.

When kalkül is the better choice

To be fair: kalkül is a genuinely good free offer for a one-person business in Austria — invoices, the small-business rule, BAO compliance and even cash-basis accounting cost nothing, and the vendor commits to keeping existing accounts' free features free. If you write a handful of invoices a month, chase them yourself and work only in Austria, you do not need Billy.

See all kalkül alternatives

Frequently asked questions

Is Billy an alternative to kalkül?
Yes. Both produce compliant Austrian invoices. The difference: kalkül is a free form-based tool with no AI features where you send reminders manually. Billy creates invoices from an AI prompt, chases payment automatically, and also covers Germany and the US.
How much does kalkül cost?
kalkül's core features are permanently free; a voluntary "supporter" subscription unlocks design customization and some extras, but the vendor does not publish its price — it is shown in the app. Billy costs from €9 per month, including the AI assistant and automatic dunning.
Are Billy invoices compliant in Austria?
Yes. Billy produces invoices with all mandatory fields under §11 öUStG, small-business invoices (§6 (1) 27 öUStG) and reverse-charge invoices (§19 öUStG, or §13b UStG for Germany).
Can I try Billy for free?
Yes — 7 days free, no credit card. There is no permanently free plan.

AI that also thinks about getting paid

Try Billy free for 7 days — no credit card.

Legal notice: general information, not legal or tax advice within the meaning of the German StBerG or RDG; no client relationship arises. No warranty as to accuracy, completeness or currency. Liability is excluded to the extent permitted by law; intent, gross negligence and injury to life, body or health remain unaffected. For your own case, your tax adviser or lawyer governs.