Meta Tech ProviderCompared · Vietnam
Voice AI platforms compared, for Vietnamese businesses
A Vietnamese business should check five things: whether the voice speaks Vietnamese well enough for your region, what you do about Zalo, whether you can keep your number, what the advertising-call decree says, and how the new personal data law applies. Below, ThinnestAI answers each check and is then set against three developer platforms, with the date we read the sources.
What to check
Five things to check before you choose, in Vietnam.
Put the last column to every supplier you are weighing, ThinnestAI included.
| Check | Why it matters in Vietnam | ThinnestAI | Ask any supplier |
|---|---|---|---|
| Vietnamese on the phone | Many calls come from people who are not in the room, such as a guest abroad, a buyer in another time zone or a family booking for a parent, and speech differs between the north, centre and south. | Voice agents speak Vietnamese, English and Mandarin, and Korean, Japanese and Thai are among the 50 voice languages. We claim the language, not a northern, central or southern accent. Listen in the voice library, ring the agent from your browser and have a native speaker from your own region try it. | Can I hear Vietnamese voices before I commit, and have a speaker from my region test the agent? |
| Zalo or WhatsApp | Zalo is widely used in Vietnam, and we found no reliable figure for how business customers split between Zalo and WhatsApp. | We do not integrate with Zalo, so the agent cannot answer Zalo Official Account messages. It answers the phone, WhatsApp and website chat. WhatsApp suits guests, buyers and visitors from abroad; keep Zalo for your team if your domestic customers write there. | Can you answer messages on Zalo, and if not, which channels does the same agent cover? |
| A number you can keep | A hotel, clinic or factory usually has one number printed on signs, invoices and booking pages, and callers abroad dial it with +84. | Use a number on your own Twilio, Telnyx or Plivo account, or forward calls to one from your current line. We don't sell Vietnamese numbers, and we have not verified which Vietnamese numbers those providers can hold or port in, so forwarding is the simplest start. Transfer to a person and voicemail detection don't work on an imported Twilio number. | Can the agent answer the number my customers already ring, and how do I test it before I move anything? |
| Advertising-call rules | Vietnamese legal press and law-firm pages report that Decree 91/2020/ND-CP allows advertising calls only to people who agreed in advance and requires a check of the do-not-advertise list, joined by SMS to 5656. Press quotes Article 13 as limiting advertising calls to 8:00 to 17:00. A draft replacement decree appeared in September 2026 (read 25 October 2026, not from the official text). | The platform has no calling window of its own: you set hours per campaign on the called person's clock, keep your own do-not-contact list and write the opening line. It does not check the national list or store proof of consent. We could not verify how an AI voice agent is classified, so plan on the stricter view. | Who checks the do-not-advertise list before a campaign, and where is the proof of consent kept? |
| Personal data and recording | The Law on Personal Data Protection, No. 91/2025/QH15, has applied since 1 January 2026. Summaries we read say silence is not consent, you must be able to show proof of consent, and sending data abroad needs an impact assessment. | Recording is a per-agent switch that stays off until you turn it on, and the opening line is yours to write. We support region deployments for enterprise customers, and we make no claim that the product meets Vietnamese law. Ask a Vietnamese adviser, and read the privacy policy. | Is recording off by default, and what do you give me in writing for the transfer impact assessment? |
Side by side
ThinnestAI and three developer platforms, for Vietnam.
Cells about other companies come from their own documentation, read on 25 October 2026.
| ThinnestAI | Vapi | Retell AI | Bland AI | |
|---|---|---|---|---|
| What it is | A managed agent with a shared inbox, campaigns and a call log | A developer platform that connects speech, language-model, voice and telephony providers | A developer-first voice agent platform | Voice agents with Pathways branching flows |
| Channels | Phone, WhatsApp, website chat, Telegram: one agent, one memory | Voice-focused | Voice and chat | Voice and SMS |
| Price shape | Flat per-minute rate — see pricing | A platform fee per minute plus the providers you choose | Priced per component | Bundled per connected minute |
| Phone numbers in Vietnam | Bring a number you own on Twilio, Telnyx or Plivo; we don't sell Vietnamese numbers | Free numbers use US area codes; outbound calls and other countries use a number imported from a carrier such as Twilio or Telnyx | Sells numbers in the US and Canada only; other countries use your own provider | Sells numbers in the US and Canada; for other countries its documentation says to contact support |
| Languages for Vietnam | Voice in Vietnamese, English and Mandarin (Korean, Japanese and Thai too); chat replies in 37 languages, including Vietnamese and English but not Mandarin | Depends on the speech and voice providers you choose | Depends on the voice and speech providers; the dashboard greys out unsupported choices | Its site states 40+ languages; check yours on a test call |
| Agent setup | Tabbed settings, no flow canvas | Visual Workflows builder | Conversation Flow builder | Pathways branching flows |
| Shared inbox and human takeover | Yes | No | Not checked | Not checked |
| Billing | US dollars, by card | US dollars | US dollars | US dollars |
Read on 25 October 2026 from each company's own pages: Vapi (phone calling, multilingual); Retell AI (purchase a number, language); Bland AI (purchase a number, site). Products change; check each page before you decide. Prices are not compared here: ours are on the pricing page, and theirs are on theirs.
Other options
Other kinds of supplier in Vietnam.
Kinds of supplier, not companies. Each is the right call for someone.
An in-house or outsourced call team
Vietnamese-speaking staff know the regional accents, can handle a guest who is upset and can arrange a pickup on the spot. It is the better call when every caller needs a person. It cannot cover midnight calls from abroad cheaply or take many calls at once.
A local telephony supplier
A local phone or call-centre system supplier can hold Vietnamese numbers, route calls to staff and record them. It is a plain way to start and keeps the number where it is. A menu or queue does not answer questions or book a visit by itself.
A chatbot built around Zalo
If most customers message you on Zalo, a supplier whose chatbot works inside Zalo covers the channel we do not. It suits a business that lives on chat, and it will not answer your phone.
Plainly
Who should pick what.
ThinnestAI fits when
- Calls and WhatsApp from guests, buyers or visitors abroad reach you at all hours, and you want one agent and one history for both.
- You want Vietnamese, English or Mandarin by voice, with the voice chosen from a library you can search and listen to first.
- You are a small hotel, clinic, tour operator or factory that needs a managed product, with a call log, transcripts and campaigns you set hours for.
Something else fits better when
- Most of your customers write to you on Zalo. We have no Zalo integration, so use a Zalo tool for those chats and keep our agent for calls and WhatsApp.
- You need an exact northern, central or southern accent. We claim the Vietnamese language only; a person from your region is the safer choice.
- Your buyer asks for a certificate we do not claim, or every caller needs a person from the first word.
Questions
Common questions.
Does the agent work with Zalo?
+
Do the other platforms sell Vietnamese numbers?
+
Are AI sales calls allowed in Vietnam?
+
Do you bill in Vietnamese dong?
+
Test it on your own calls in Vietnam.
Create an agent, give it your own information, and ring it from your browser before you connect a number. Then put the same test to the others.