An IllyVoIP Voice Agent can detect and switch between the languages you select in Studio. Configure the main language and additional languages together, then review the words the agent is expected to say. One selected voice is used across those languages; choosing a language does not translate saved text.
Before you change a working agent
You need Voice Agents management access and a clear list of languages your business can support. Agree who will receive a human handoff in each language. Keep a private copy of important greetings and knowledge before editing, and choose a quiet time for any change that will affect live calls. These instructions configure the Voice Agent, not the language of your Portal account.
1. Choose the intended languages
- Open Voice Agent Studio and select the correct agent, or use New Agent for a new configuration.
- In Basics, choose Main language. This is the primary language for the agent configuration.
- In Additional languages, select only the extra languages the assistant should recognize. Check the selected values rather than assuming every language displayed in the list is enabled.
- Choose an offered Voice. Listen to its sample if useful, but do not treat one short sample as an acceptance test for all selected languages.
2. Review the actual text callers will hear
Check the opening greeting, Collect input prompts, Play audio/text steps, transfer explanations and closed-hours wording. A fixed greeting remains the text you wrote. If it introduces the service in English, adding another language does not silently rewrite that greeting. Write an appropriate opening for your audience and avoid a long list of languages that delays every caller.
Keep business knowledge consistent across the intended languages. Product names, opening hours, eligibility and prices should describe the same service. Do not add contradictory copies of a rule just to repeat it in several languages. Have someone competent in the language review wording where accuracy matters; fluent speech is not proof that a business answer is correct.
3. Prepare an honest fallback
Decide how the conversation should proceed if a caller uses a language outside your selected set, mixes languages or asks for a person. Configure a real reachable handoff and explain its availability honestly. A note saying “transfer to a colleague” does not create a destination or guarantee that the colleague speaks the caller’s language. Avoid promising automatic translation between the caller and a human recipient.
4. Apply and check the saved configuration
- Review the main language, additional selections, voice, greeting and relevant flow branches together.
- Use the offered Update or Publish action once. Resolve validation errors and wait for the resulting state. Audio preparation can be separate from merely selecting an option.
- Reopen the same agent and verify the saved selections. A highlighted dropdown in an unsaved editor is not proof of an applied change.
- Before attaching a new incoming number, confirm the agent’s published state and the intended incoming destination.
5. Check each language with a small test plan
For each selected language, arrange an authorized call and check a normal question, an unknown question and a request for a person. Include a caller who changes language mid-conversation and a short ambiguous response. Verify the answer, language and final handoff separately. Real calls and enabled analysis can incur charges.
If the result is wrong, first check the selected agent, the stored prompt text, enabled knowledge and completed update. Do not keep adding languages to fix a broken transfer. Give Support the agent reference, selected languages, time/timezone, public call reference and a short sanitized example; do not send the full customer conversation unnecessarily.
Related guides
- Prepare an AI voice agent
- Build and maintain your Voice Agent knowledge
- Connect Voice Agent flows, integrations and reports
Reviewed 12 October 2026 against the current IllyVoIP controls, implementation and applicable references. Available options depend on account permissions and service state.