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AI phone agents in French

ThunderPhone supports French across the customer experience: agents speak and understand French on calls, the dashboard has a French interface, and the docs site has a dedicated French edition. A team can build in French, operate in French, and give callers a fully French line.

French is one of ThunderPhone's 47 supported voice languages. It is an included language, so selecting French does not add a language surcharge to the Spark, Bolt, or Storm engine rate.

French voice availability and pricing

The current catalog includes eight voices that support French:

  • six multilingual voices included on the French language path; and
  • two premium French voices, Pauline and Marc.

Because French is included, calls bill at the engine rate alone — Spark 2¢, Bolt 5¢, or Storm 9¢ per minute, pay as you go, no subscription. The optional premium French voices add 3¢ per minute on top of the selected engine rate. All figures are illustrative and exclude telephony and other optional charges.

Preview each candidate voice in the builder, then test it against the calls you expect. Evaluate names, addresses, numbers read aloud, liaison and elision on the phrases that matter, English loanwords, and the register your callers expect — the difference between tu and vous belongs in your prompt, not to chance.

French in the dashboard and documentation

French is a shipped dashboard locale, not just a call setting. Teams can configure prompts, review calls and transcripts, manage integrations, and operate the account in the French interface.

ThunderPhone also publishes a dedicated French documentation edition on its docs site, so French-speaking builders get localized product guidance in addition to a French-speaking agent experience.

French and English in one call

An agent can start in French and switch automatically when a caller moves into a configured additional language such as English — and switch back when the caller returns to French. The reverse also works for an English-first line serving French-speaking callers.

The chosen voice must support every selected language. For bilingual lines, test full calls in both languages plus realistic switch points: a caller who starts in French but spells an email address, product name, or street address in English is a common case worth rehearsing.

Sample French call experience

The following flow is written in English to describe the caller experience.

Agent starts in French: Greets the caller, identifies the business, and asks how it can help.

Caller answers in French: Says they need to change tomorrow's appointment.

Agent continues in French: Confirms the caller's name, looks up the approved scheduling action, and offers two available times.

Caller switches to English: "Could you send the confirmation to my work email?"

Agent switches to English: Repeats the email address back and confirms where the notice will be sent.

Caller returns to French: Confirms the new time and asks one final question about arrival.

Agent returns to French: Answers from the approved instructions, repeats the confirmed date and time, and ends the call according to the business's instructions.

The language switch happens within the same call; no separate number or phone-tree language menu is required.

Build and test a French agent

  1. Set French as the primary language, or add it to an agent's additional languages.
  2. Choose one of the eight voices that supports the full selected language set.
  3. Write the operating prompt with the register, questions, tool actions, and fallback behavior you expect — including how the agent should address callers.
  4. Attach approved French source material where localized answers matter.
  5. Run French-only, English-only, and mixed-language simulations.
  6. Review pronunciation, transcripts, tool actions, transfers, and escalation behavior before deployment.

Frequently asked questions

Does ThunderPhone support French voice calls?

Yes. French is one of ThunderPhone's 47 supported voice languages and currently has eight compatible voices in the catalog.

Does French cost extra as a language?

No. French is an included language, so it adds no language surcharge to the engine rate — Spark 2¢, Bolt 5¢, or Storm 9¢ per minute, before telephony and other optional charges.

Are premium French voices available?

Yes. The catalog currently lists two premium French voices, Pauline and Marc, each adding 3¢ per minute. The other six compatible voices use the included French language path.

Is the dashboard available in French?

Yes. French is a shipped dashboard locale.

Are the ThunderPhone docs available in French?

Yes. ThunderPhone publishes a dedicated French documentation edition on its docs site.

Can a French agent switch to English during a call?

Yes. Add English as an additional language and choose a voice that supports both. The agent switches automatically when the caller changes language mid-call.