WhatsApp API cost calculator.
Plug in your real numbers. See what your WhatsApp bill would actually look like on Mossmoon’s flat-per-line pricing versus a Business API path billed per conversation per country per category. No marketing fluff, just the math.
How we compute each side.
Flat per line, all in.
lines × $15 (or × $20 with voice calling). Unlimited inbound and outbound. No per-message, per-conversation, per-country, or per-seat fees. First line is free for 7 days.
Per-conversation plus platform fee.
(lines × conv/line × per-conv rate) + (lines × $25). Per-conversation rate varies by country and category per Meta’s published rate card (approximated as of mid-2026). $25/line/mo platform fee is a conservative representative number for BSPs like Twilio, 360dialog, WATI, or Charles. Your real BSP bill often includes more (agent seats, integrations tiers, support tiers).
- This is an estimate. Real bills depend on your exact traffic split (utility vs marketing, country mix per recipient, conversation length), your BSP’s margin, and Meta’s rate-card updates.
- Mossmoon’s personal-API path doesn’t serve high-volume mass broadcast use cases. For those, the Business API is the structurally right tool and the per-conversation math fits the workload.
- For low-volume scenarios (many lines, few conversations each), Business API can come out cheaper. The calculator will say so honestly when it does.
Use cases where the cost delta is largest.
Multi-tenant agencies
Onboarding 25-100+ client lines, each with hundreds of conversations a month. Flat $15/line scales linearly; per-conversation BSP cost compounds across all clients.
Marketing agencies →International conversational support
Heavy WhatsApp traffic in EMEA, LATAM, or India. Per-conversation Business API rates per country add up fast. Flat per-line collapses the variable cost.
Read the path comparison →Real-estate or recruiting agent teams
Each agent has their own line. Conversations per line moderate, but $25/line BSP platform fees stack. Flat $15/line wins on both axes.
Real estate guide →About the math and the model.
Two components: per-conversation cost (number of conversations multiplied by Meta's published rate for the selected country and category) plus a representative monthly platform fee per line ($25 by default, covering a BSP's typical hosting tier).
Real BSP bills include extras the calculator doesn't model: agent seats, template-approval workflows, integrations tiers, support tiers. So the BSP-side number is conservative; your actual bill is often higher than what we show.
$15 covers one active WhatsApp line per month: unlimited inbound and outbound messages, hosted always-on connection, signed webhooks, full REST API, and the first line is free for 7 days. Voice calling is +$5/line/mo with unlimited minutes. No per-message fees, no per-conversation fees, no per-seat fees on your internal team using the dashboard.
Approximated from Meta's published WhatsApp Business API conversation rate card as of mid-2026, weighted across country and category (marketing, utility, authentication, mixed conversational). Meta updates these periodically; for current values, see Meta's official rate card.
The relative ordering by country and category stays stable even when rates shift, so the calculator's directional answer remains useful even after rates update.
Two structural reasons. First, our pricing model is flat per line, not per conversation, so message volume doesn't compound the bill. Second, we don't sit on Meta's Business API, so there's no per-conversation layer at all. See /blog/whatsapp-business-api-vs-personal-api for the deeper architectural comparison.
Low-volume scenarios where you have many lines but very few conversations per line. Mossmoon charges per line regardless of usage; the Business API charges per conversation. If you're running 100 lines that each send 20 conversations per month, the per-conversation math may come out lower than $15/line/mo flat.
More importantly, Business API is the structurally right tool for mass-broadcast workloads (OTPs at scale, shipping notifications, marketing blasts) where templates and per-conversation pricing fit. Mossmoon doesn't serve that workload at all. The calculator's job is to show you the cost difference for conversational use cases.
Separate, toggle in the calculator. Voice-calling-enabled Mossmoon lines are $20/line/mo (Mossmoon messaging is $15), unlimited minutes, no per-minute fees. Useful for first-call qualification, FSBO outreach in real estate, phone screens in recruiting, international coaching calls. Business API doesn't natively offer WhatsApp voice as a packaged feature in most BSPs.
Yes, click "Copy link" in the result panel. The URL encodes your lines, conversations, country, category, and calling choice, so teammates open the same scenario and see the same numbers.
The numbers check out? First line is free for 7 days.
Related reading: Business API vs personal API · WhatsApp vs SMS · Twilio comparison · WATI comparison