WhatsApp Business app vs the API (Wati vs respond.io): when do you actually need to pay?

The free WhatsApp Business app has no AI and one phone. The API path buys AI agents, teams and broadcasts, via a BSP subscription plus Meta's per-message fees. Checked 15 Jul 2026.

The short answer: for most Singapore small shops, the free WhatsApp Business app is the right tool. One number, one phone, away messages, quick replies, a catalogue, S$0. What it can't do is AI. Nothing in the free app answers a customer by itself. The moment you really need an AI agent replying at 2am, several staff on one number, or broadcasts beyond the app's limits, you're on the WhatsApp Business Platform (the API). That means a BSP subscription (Wati, respond.io and friends) plus Meta's per-message fees on top. The stack starts around US$79–159 a month on annual billing before Meta's fees, so the line matters. Here's where it sits.

At a glance (checked 15 Jul 2026)

	Free app	API via respond.io	API via Wati
Software cost	S$0	Starter US$79/mo (5 users) · Growth US$159/mo (10 users) · Advanced US$279 — annual billing; monthly ~20% more	Growth / Pro / Business tiers (geo-priced — read the live page; ~3–5 users incl., extra users US$24–69)
Meta message fees	none (normal app use)	on top, billed by Meta	on top — "additional charges apply for messages"
AI answering customers	✗ none — away/greeting messages are static; quick replies are manual shortcuts	✓ included at no extra cost on Growth+ — AI Agents, AI Assist, summaries	✓ via paid add-ons — "Astra AI Agents… priced separately" + AI Co-pilot credits
Team on one number	1 phone (+ linked devices, small-team workable)	✓ built for it	✓ built for it
Who it's for	owner-operated shops	service teams wanting bundled AI	broadcast-heavy sellers

How Meta's fees actually work (the part everyone garbles)

Meta's own pricing page and rate cards say the Platform charges per delivered message, by category. Marketing, utility and authentication templates are paid (volume-tiered), and rates vary by market–category pair. Singapore has its own rate card. Now the one that changes the economics: service messages, meaning replies to a customer within the 24-hour customer-service window, are free. So an SME that mostly answers inbound enquiries pays Meta almost nothing, even on the API. The Meta bill really arrives when you broadcast marketing at scale. Your budget is the BSP subscription plus (marketing sends × your rate-card price). Read the SG rate card with your actual send numbers before you believe anyone's "from" price. Including ours.

What you're actually buying

The free app does more than vendors admit: business profile, catalogue, away and greeting messages, labels, quick replies. Everything an owner-operated counter needs, set up in twenty minutes (our playbook). Its limits: no AI, effectively one person properly, no compliant mass-messaging, no integrations.

respond.io is a shared team inbox across WhatsApp, IG and Messenger, with automation built in. And here's what's decisive at its price. Its pricing page says "AI usage is included at no extra cost on Growth, Advanced and Enterprise". AI agents answering, AI assist for drafts, conversation summaries, and no separate AI meter. USD pricing is printed plainly on the page, which is rare in this category, and to its credit.

Wati is WhatsApp-first and strong on broadcasts, a favourite with sellers pushing campaigns. Its AI (the Astra agents) and its AI co-pilot are paid add-ons, priced separately. Its page geo-serves currency, so read it from Singapore yourself. And Meta's fees ride on top, as everywhere.

The decision-flips: (1) AI is the real upgrade trigger, not "being professional on WhatsApp". If nobody needs a robot answering or five agents on one number, the free app plus the playbook wins at S$0. (2) On the paid path, look at the shape of the AI cost: bundled (respond.io) or add-on (Wati). As AI conversations grow, the add-on model's bill grows with them. Get Astra's current add-on price in writing and compare at your volume. (3) Inbound-heavy versus broadcast-heavy decides your Meta bill more than your BSP choice does.

Singapore-specific notes

WhatsApp is the customer channel here. Which is exactly why paying for the API before you've outgrown the free app is such an easy S$100+/month mistake to make.
Rates are market-specific. Pull the Singapore rate card and multiply by your real monthly marketing sends. That number often exceeds the BSP subscription.
PDPA: API-path chats flow through your BSP's cloud, so add it to your privacy note. And broadcast marketing needs consent, the same rule as email: collecting a number for an order isn't consent to market to it.
Vendors here quote "WhatsApp automation packages" at four and five figures. The software above is US$0–279/month. Bring quotes to the markup check.

Which one for which business

Owner answers the phone, under ~30 chats/day: the free app + the 20-minute playbook. Done, S$0.
Small service team (3–10) drowning in inbound, wants AI to catch the repeats: respond.io Growth. The bundled-AI price is the whole point. Mostly inbound means Meta fees near zero.
Product seller running broadcast campaigns to opted-in lists: Wati. But price Astra's AI add-on and your rate-card sends first.
Just want the website/FAQ handled by AI: that's cheaper off-WhatsApp. See Tidio vs Chatbase vs DIY.

You might need neither if…

…this is really an after-hours problem. The free app's away message answers at 2am. A Google Form link captures the enquiry. The lead-capture playbook pings your phone. That covers the classic "we lose enquiries at night" pain for S$0. No BSP and no Meta fees. Nothing new to learn, either.

Your first move, step by step

Count a real week: inbound chats a day, how many people answer, and how many broadcasts you'd send a month if you could.
Under ~30/day with one answerer? Do the free-app playbook today.
Over that? Trial respond.io (its prices are public) and Wati in the same fortnight. Wire both to a test number, not your live one.
Pull the SG rate card and work out Meta's fees on your broadcast plan.
Decide on total monthly cost at your volume: subscription, add-ons and Meta. Not the "from" price.

FAQ

Can I keep the free app and add the API later? Yes. Migrating a number to the Platform is standard BSP onboarding. You lose app-side chat history, so export first. Starting free costs you nothing but that.

Do I need Meta verification and template approvals? On the API path, yes. Business verification and per-template approval for the paid categories are part of BSP onboarding. Budget days for setup, not minutes.

Is the API PSG-fundable? Chatbot builds via pre-approved vendors sit in PSG's chatbot category (details). BSP subscriptions themselves are buy-direct. Do the grant maths first: calculator.

Bulk-sending via the normal app with tricks? Don't. It's against WhatsApp's terms, it gets numbers banned, and in a consent-based regime it's also the fastest way to burn the channel your customers actually like.

Next step

Do the one-week count. If it says "free app", the playbook has you covered by tonight. If it says API, run the two-BSP fortnight with the SG rate card open, and get every AI add-on price in writing before you sign anything.