AI voice agents that answer and make your calls, 24/7

What is an AI voice agent?

An AI voice agent is a phone assistant built on a language model, speech recognition and a synthetic voice. It holds a real conversation instead of reading a menu: the caller can say what they need in their own words, interrupt, or change topic, and the agent answers or asks a follow-up question.

What makes it useful for a business is the same thing that makes a chat AI agent useful: grounding. The agent gets instructions (who it is, what it may and may not promise), a knowledge base with your real prices, policies and services, and a set of tools it is allowed to use. Without those three pieces it can only make small talk.

An IVR is a fixed menu: callers press 1 or say a keyword and get routed. An AI voice agent understands the request in the caller's own words, resolves it when it can, and transfers it with a summary when it cannot.

• IVR: menus and keywords, routes the call, resolves nothing on its own.
• AI voice agent: understands free speech, answers from your knowledge, records what happened.
• AI voice agent with hand-off: knows its limits and brings in your team.

Inbound calls: an agent that always picks up

On inbound calls, the AI agent answers on a phone number Hellou provisions for your account and points at the agent. Callers get an answer at night, on weekends and when every person on your team is already on another call, up to your plan's number of simultaneous calls.

During the call, the agent can search your knowledge base, update the contact's name, email or phone number, set custom attributes, add labels and route the conversation to a team. It is the same native AI agent as in chat, so it can also use the tools you connected to HellouOne, such as your CRM.

When a person should take over, the agent transfers the call to the destinations an admin configured, within your business hours. If the AI cannot take a call at all (the agent is off, the line is busy or the spending cap was reached), the call falls through to your account's normal human routing instead of ringing out.

• After-hours reception that answers common questions and takes details.
• A first line for support that resolves the routine calls and transfers the rest.
• Overflow when your team is busy, so no caller waits in silence.

Outbound voice campaigns

Outbound campaigns let the AI agent call a list of contacts for you: payment reminders, appointment confirmations, lead follow-up or a short survey. You upload a CSV with one row per contact and any variables the script needs, such as the name or the company, and choose the days, hours and time zone the campaign may call in.

The opening of every call follows a fixed order. The agent waits for the person to speak, asks whether it is speaking with the contact by name, gives the recording notice, and only then says why it is calling. If the person who answers says they do not handle the matter, the call is recorded as wrong person and the campaign moves on to the next contact at the same company. We wrote about why this order matters and how campaigns reach the right person.

Answering-machine detection hangs up or leaves a voicemail, depending on what you choose, and retries the contact later. You set the maximum attempts per contact and the delay between retries. Every contact ends with an outcome, callbacks are tracked, and you can pause, resume, cancel or archive a campaign and export the results as CSV.

• Scheduling window by day, hour and time zone (scheduled launches).
• Retries with a maximum number of attempts and a delay between them.
• Concurrency per campaign, inside your plan's simultaneous-call limit.
• Live monitor while the campaign runs, and campaign reports after.
• Test calls only to up to three verified test numbers before launch.

Consent and compliance on outbound calls

Outbound calling is regulated, and the rules are part of the product rather than a checklist on the side. Before a campaign can launch, an admin has to confirm that the contacts gave the consent the law requires. The do-not-call list is always enforced, and when someone says on the call that they do not want to be called again, the opt-out is recorded.

Compliance rules are on by default. For collection calls in Colombia, they follow Ley 2300 de 2023, which limits collection contacts to Monday to Friday from 7:00 a.m. to 7:00 p.m. and Saturdays from 8:00 a.m. to 3:00 p.m., with no contact on Sundays or holidays. Daily and weekly attempt caps limit how often the same person is called. An admin can turn a rule off, and that change is audited.

The agent also introduces itself as a virtual assistant at the start of every call. People should know when they are talking to an AI, and the opening is the same on every call, so it is easy to audit.

Voices and languages

Every plan includes a standard voice. Premium voices are natural voices with a Colombian accent: six of them, female and male. They are included on the 10K and 20K plans and can be added to the 2.3K and 5K plans. Standard and premium minutes are counted separately, so you can see what each one uses.

The agent speaks Spanish (Colombia, Mexico, Spain and Latin American Spanish) and US English. You choose the voice in the AI agent editor, in the Phone calls section, next to its instructions and knowledge.

What you get after every call

Every call leaves a record your team can use. The full transcript covers the whole call, including the part after a transfer to a person, and an AI summary appears on the call card, so whoever picks up next starts with context. Calls are recorded and listed in the call history.

The AI call report scores calls against criteria you define, such as whether the agent confirmed the appointment or gave the recording notice, so supervisors review the calls that need it instead of listening to everything. Campaign metrics separate real conversations from calls that never became one.

• Transcript, AI summary and recording for every call.
• An outcome for every campaign contact, exportable as CSV.
• AI call report with your own scoring criteria.
• Webhooks when a call ends, when its summary is ready and when a campaign contact is resolved.

How AI voice agent pricing works

HellouOne AI voice agents cost USD 499 to USD 2,999 a month for 2,300 to 20,000 minutes (USD 0.217 to USD 0.150 per minute), with AI, voice and Colombian telephony included and per-second billing. Plans are priced by included minutes, with the AI, the voice and telephony in Colombia in the same monthly price. There is no separate platform fee, setup is included, and billing is per second from the moment the call is answered. Minutes spent in voicemail and in transfers count too.

Bigger plans lower the price of every minute: from USD 0.217 per minute on Hellou 2.3K to USD 0.150 on Hellou 20K. They also raise the number of calls the agent can hold at the same time, from 5 to 30, which matters as much as minutes for campaigns.

Going over your plan never cuts a call. You get an email and a notice in the admin panel at 80% and 100% of your minutes, calls keep working, and each additional minute is billed per second at your plan's additional-minute rate, from USD 0.25 on Hellou 2.3K to USD 0.19 on Hellou 20K. A spending cap stops the AI before the bill surprises anyone: by default it allows additional use of up to 50% of the plan's minutes (1,150 extra minutes on 2.3K), you can change it, and at the cap inbound calls go to your team and outbound campaigns pause. How metering and caps work.

Prices in USD, before taxes, effective October 2026. The full plan details, premium voices and terms are in the plans section above.

How to estimate the minutes you need

Minutes are calls multiplied by their average length. Take last month's call count from your phone system or carrier, multiply it by the average answered-call duration, and add the outbound campaigns you plan to run. Only answered time is billed, so unanswered attempts do not count.

A worked example: a clinic receives 1,200 calls a month that average 2.5 minutes, which is 3,000 minutes. It also wants a monthly reminder campaign to 800 patients, with about 600 answered calls of 1.5 minutes, another 900 minutes. That is 3,900 minutes. Hellou 5K (USD 999) covers it with 1,100 minutes to spare. On Hellou 2.3K the same month would mean 1,600 additional minutes, about USD 400 on top of USD 499, and it would reach the default spending cap at 3,450 minutes.

Then check concurrency. If calls arrive in bursts, for example at 8 a.m. on Mondays, or a campaign has to finish in a few hours, the number of simultaneous calls can decide the plan before the minutes do. If you are not sure, we estimate it with you from your own numbers.

How to choose an AI voice agent

Demos all sound good, so judge AI voice agents on what happens in month two. These are the criteria worth checking with any provider, whatever brand you are comparing:

HellouOne bills per second, holds 5 to 30 simultaneous calls depending on the plan, lets you set the cap, and keeps calls, chats and WhatsApp in one shared inbox with the same AI agent.

Setting it up in HellouOne

Voice plans are set up with our team: we provision the phone line, configure your first AI agent's voice, instructions and knowledge with you, and test it before it takes real calls. Setup is included in every plan.

Once it is live, everything sits in the Voice menu of HellouOne: AI phone lines, AI calls, the AI call report, voice campaigns and their reports, the live monitor, compliance settings, call history and phone numbers. The voice and the call behavior are set in the AI agent editor, in the Phone calls section.

Developers can work with calls, AI phone lines, voice campaigns and the AI call report through the HellouOne API, documented in English and Spanish at one.hellou.ai/docs. Voice data is also readable from the HellouOne MCP server; launching campaigns in bulk stays in the app on purpose.