A WhatsApp Business account can’t message every opted-in customer just because the opt-in exists. Meta caps how many unique numbers a business can message outside an open conversation, shares that cap across every phone number on the account, and raises it only by messaging more people well — never by asking.
Why the number on day one is smaller than it looks
A new WhatsApp Business portfolio starts with a messaging limit of 250 — “the maximum number of unique WhatsApp user phone numbers your business can deliver messages to” in a moving period, not a quota that resets on a billing date (Meta for Developers: Messaging limits). That 250 also isn’t per number: Meta states limits are “calculated and set at the business portfolio level” and “shared by all business phone numbers within a portfolio.” Connecting a second WhatsApp line to the same account doesn’t add capacity — it splits the same 250 across two lines instead of one.
How the cap actually grows
Meta lists two ways to move from 250 up to 2,000: verify the business (or have the partner who onboarded it verify it), or “send 2,000 delivered messages outside of customer service windows to unique WhatsApp user phone numbers… within a 30-day moving period, using templates with a high quality rating.” Either path only starts a review — Meta checks message quality before approving the increase.
Past 2,000, scaling runs automatically rather than on request. Meta raises the limit when a business is “sending high-quality messages across all of your business phone numbers and templates” and has “utilized at least half of your current messaging limit” in the preceding 7 days. Meet both at once and “your portfolio’s limit increases by one level within 6 hours” — climbing 2,000, then 10,000, then 100,000, then unlimited. Nothing in Meta’s own page describes a quality drop pulling the limit back down; the mechanism it documents only moves up.
Where this bites a chat-commerce waitlist
A shop that built a restock waitlist with a proper WhatsApp opt-in can still hit the 250 ceiling the first time a popular item comes back — 300 opted-in numbers on an unverified new account means 50 of them get an API error, not a delayed message. The same ceiling catches booking reminders and any other business-initiated send once a list outgrows the current tier, whatever the template’s category says. A correctly approved utility template still can’t reach more unique numbers in a day than the account’s current limit allows.
ตั้งค่าใน 1CS
1CS connects a WhatsApp number through WhatsApp Cloud API, either with Meta’s own Quick Setup (log in to Meta, click “Connect with WhatsApp Business,” and 1CS sets the webhook and number automatically) or by entering the Phone Number ID, Business Account ID and API key by hand — either way, a WhatsApp Business account and a Meta Business account need to already exist and be ready before that step. Business verification, one of Meta’s own scaling paths to 2,000, happens inside that same Meta Business account, not inside 1CS. After connecting, 1CS’s setup checklist includes testing an outbound template send — use that test to confirm the template’s approval status in the same pass, since a rejected or pending template fails independently of the messaging limit. The click-by-click flow is in 1CS’s WhatsApp inbox guide (Thai only); WhatsApp is one of 1CS’s connected channels.
A rollout checklist to copy
Before messaging a list bigger than a few hundred numbers, work through this once:
- Check the account’s current messaging limit in WhatsApp Manager under Account tools, rather than assuming it’s still 250.
- If the list is bigger than the limit, send in daily batches of roughly half the limit — using half of it in 7 days is one condition for the next tier.
- Keep the same approved, high-quality template for the whole batch, so it’s clear what quality signal the account is actually sending.
- Message the most recently active opted-in numbers first; a list gone cold for months is more likely to get ignored or blocked, which works against that same signal.
- Re-check the limit after a week before sizing the next batch — a tier that already moved up changes how big it can be.
None of this replaces the opt-in and template-approval work — it’s the next step, once a list has grown past what a 250-number account could ever reach in one send.
