Trengo vs Zendesk: Priced by Conversation or by Agent

The short answer: if eight people answer a queue that arrives mostly on WhatsApp, and the shop phone has to keep its WhatsApp chats, Trengo fits: Boost costs €349 a month on monthly billing, or €299 billed annually, for 10 users and 500 conversations a month, and Coexistence runs one number in the WhatsApp Business app and in Trengo at once (Trengo pricing, Coexistence). Zendesk fits when calls, email and a help centre weigh as much as WhatsApp: Suite Team is $55 per agent a month billed yearly, $440 for eight, telephony included (Zendesk pricing). Both checked on 26 October 2026.

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Three readings from your own accounts:

1. Last month's conversations, priced. Trengo counts a conversation as any reply inside a 7-day window (pricing page). For example, 900 a month on Boost billed monthly is the 500 included plus 4 blocks of 100 at €18, so €349 + €72 = €421. Zendesk ignores volume and counts people: 8 x $69 = $552 a month on monthly billing (Zendesk pricing).
2. Where the WhatsApp number lives today. If it already runs on the WhatsApp Business app and sits in Meta Business Manager, Trengo can take it over without switching the app off (Coexistence). Zendesk's setup says a number cannot be on the app and the WhatsApp Business API at the same time, a Meta rule (Zendesk WhatsApp article).
3. The baseline for the AI. Read 50 WhatsApp conversations from last month and mark those a saved answer would have closed. That share is the bar either AI agent has to clear.

Six rows that decide it

Read on 26 October 2026 from each vendor's pricing page and the help articles linked in the sections below.

What separates them

A bill that follows messages, or one that follows people

Trengo sells a team and a volume: Boost carries 10 users and 6,000 conversations a year, Pro 20 users and 18,000 (pricing page). Run past the allowance and messages still send, with an overage surcharge; unused conversations carry over on a yearly plan and lapse on a monthly one (conversations article). Zendesk sells seats and lets the volume float. Ten people answering 400 chats a month suit the first; ten answering 4,000 suit the second.

The number and what Meta now charges for it

Since 1 October 2026, Meta bills each service reply past the first 1,000 per phone number a month, on every provider (Trengo WhatsApp pricing). Zendesk's notice says the same change applies through its platform and that Meta's fees sit apart from Zendesk's (Zendesk notice). The platform does not change Meta's rate; habits do. Trengo's own advice is to turn off "Send customer replies on Enter", so one answer leaves as one message rather than several.

Two meters for the AI

Trengo prices a conversation with an AI surcharge at €0.30 on monthly billing, €0.25 on yearly (pricing page), without saying whether a handed-over conversation still carries it; ask before Autopilot. Zendesk includes 5 resolutions per agent on Suite Team and bills the rest only when a language model verifies the AI solved the request (resolution tiers). One prices conversations; the other prices outcomes it grades itself.

Prices on 26 October 2026

Checked on 26 October 2026 on the Trengo pricing page and the Zendesk pricing page, which lists dollars though Zendesk also bills in euros. Meta's WhatsApp charges come on top of both.

One agent step: the photo of a broken product

A customer sends a photo of a cracked lamp and a PDF receipt. Trengo's AI Agent can read both, recognise the damage, find the order number, then label and assign the conversation (AI Agent abilities). In Supervised Mode it only proposes: a person approves, edits or reassigns, and the reply goes out under that person's name (Supervised Mode). On Zendesk, the same job belongs to the email AI agent, which reads PDFs of up to 150 pages and PNG, JPEG, WebP or GIF images to classify a request and start a procedure; on messaging, attachment recognition is not available (agentic AI article). Either way, the refund itself stays a human decision. Once it answers alone, Article 50 of the EU AI Act wants customers told it is an AI; the LiveAgent entry sets out the rule.

Choose Trengo if your job is

• Answering a WhatsApp-first queue with up to 10 or 20 people.
• Keeping the WhatsApp Business app on the number while the team moves to a shared inbox.
• Watching the AI draft on real customers for a month before it sends anything itself.

Choose Zendesk if your job is

• Running phone, email, chat and a help centre as one ticket system.
• Paying for people rather than volume, because conversations far outnumber agents.
• Billing AI only for requests it verifiably solved.

Plans and setup: the Trengo entry. Zendesk has no entry here; see zendesk.com.

Free first, then the auto top-up

The 50-conversation baseline needs neither vendor. Then Trengo's 7-day trial asks for no card (trial page), and Supervised Mode adds no AI surcharge while a person approves every draft. Zendesk's 14-day trial asks for no card either (Zendesk homepage).

Trengo's auto top-up applies to every account: when the balance that pays Meta's fees and the AI surcharge runs out, Trengo charges the overrun plus an estimate for the rest of the cycle, up to €500 of extra balance, rounded up to the next bundle (plan and pricing article). Trengo is paid before the messages are sent, so commit a balance you chose rather than one the system extrapolated.

FAQ

Which is cheaper for 15 people?

On monthly billing, checked on 26 October 2026, Trengo Boost with 5 extra users is €349 + 5 x €30 = €499, and Pro at €599 includes 20 users and three times the conversations; Zendesk Suite Team is 15 x $69 = $1,035 (Trengo pricing, Zendesk pricing). Trengo stays cheaper until conversation blocks pile up.

Does Zendesk add its own fee to WhatsApp messages?

Its notice keeps Meta's fees separate from Zendesk's and sends you to your account manager for how they reach your invoice (Zendesk notice).

What happens when Trengo's 30 supervised days end?

The AI stops drafting, your setup is saved and nothing is charged; switch to Autopilot or ask your success manager for more time. The clock is one per account and starts the first time anyone turns Supervised Mode on (Supervised Mode).