If you're planning a bulk campaign to a US audience, you can send it by SMS or by WhatsApp. WhatsApp has rich media, read receipts and a polished brand profile. SMS has plain text and a reputation for spam filtering. On features alone, WhatsApp looks like the upgrade.
For most US lists, reach decides the question before features do. SMS lands on essentially every mobile phone in the country. WhatsApp only reaches the people who installed it and use it, and in the US that is a minority of adults, concentrated among international families, travelers and some immigrant communities. This post compares the two channels on reach, opt-in rules and cost, and covers where iMessage fills the rich-messaging gap that pushes people toward WhatsApp in the first place.
The reach problem nobody puts on the pricing page
A message that never arrives costs nothing, and it also earns nothing. Before comparing rates, look at how many people on your list each channel can reach at all.
- SMS: works on every carrier-connected phone, with no app, no account and no data connection. If you have a valid mobile number and consent, you can reach the person.
- WhatsApp: works only if the recipient has a WhatsApp account on that number. Many US contacts don't, and you usually won't know which ones until a send fails or goes undelivered.
Here's a rough way to see it. Take a 10,000-contact opted-in list. If something like a third of them actively use WhatsApp (a loose assumption for a general US audience, and yours could be higher or lower), a WhatsApp-only campaign reaches around 3,300 people. You'd still need SMS for the other two thirds. For a US-first business, you'll be running SMS either way, and WhatsApp becomes a second channel to maintain on top of it.
The exception is real. If your customers are mostly international, or you serve communities where WhatsApp is the default app for family and business, WhatsApp can beat SMS on engagement. Check your own audience before you decide. A survey question at checkout ("Prefer WhatsApp or text?") tells you more than any national average.
Opt-in and approval rules, side by side
Both channels require consent. The approval work is different.
SMS: 10DLC registration plus TCPA consent
Business texting from a regular US number (A2P 10DLC) needs a registered brand and campaign. Carriers filter unregistered traffic, so this step isn't optional. Under US law (TCPA), marketing texts need prior express written consent. Recipients have to be able to reply STOP, you have to honor it, and sends should stay inside permitted local hours.
On Ready, registration happens in-app, and most approvals take 2 to 7 days. STOP handling, quiet-hours holds and opt-out propagation across campaigns are built in. If you want the full fee breakdown, our 10DLC cost guide covers each line. If you're writing your consent language now, see 10DLC opt-in examples and sample messages.
WhatsApp: Meta's opt-in rules and template approval
Meta requires opt-in before a business messages someone on WhatsApp. Any business-initiated message outside a 24-hour window after the customer last wrote to you has to use a pre-approved template. Marketing templates are their own category and are reviewed separately. Meta also limits how many unique users a new business number can message per day. The limit rises as your quality rating holds up, and it can drop if recipients block or report you.
In practice:
| Bulk SMS (10DLC) | WhatsApp Business | |
|---|---|---|
| US reach | Nearly every mobile phone | Only WhatsApp users |
| Registration | Brand + campaign with carriers; most approvals take 2 to 7 days | Meta business verification, display name and template approval |
| Content review | Sample messages at registration; content filtering after | Every business-initiated template reviewed |
| Free-form messages | Yes, to consented contacts | Only inside the 24-hour customer window |
| Opt-out | STOP keyword, legally required | Block/report, which also hurts your quality rating |
| Rich media | MMS (photos); plain text otherwise | Images, buttons, lists, documents |
| Volume ramp | Carrier caps by trust score | Daily unique-user tiers by quality rating |
Neither channel exempts you from consent law. Treat WhatsApp opt-in as seriously as SMS opt-in, and keep your own consent records. That includes the time, the wording and the page where the person agreed.
What it costs: worked examples
SMS on Ready
Ready's Standard rate is $0.0075 per segment, plus a $0.0045 carrier fee per segment itemized separately. The rate is the same at any volume. That all-in figure excludes the optional compliance surcharge: TCPA/DNC scrubbing and landline validation are each $0.003 extra per segment when you switch them on, and both are off by default.
Example 1: a plain-text promo. A 150-character message with no emoji fits in one GSM-7 segment (the limit is 160). Sent to 5,000 opted-in contacts:
- Ready rate: 5,000 × 1 × $0.0075 = $38
- Carrier fee: 5,000 × $0.0045
- Total: $38 plus 5,000 × $0.0045
Example 2: the same list, with an emoji. A 175-character message with one emoji switches to unicode encoding. That's 67 characters per segment for multipart messages, so the message becomes 3 segments:
- Ready rate: 5,000 × 3 × $0.0075 = $113
- Carrier fee: 15,000 × $0.0045
The emoji tripled the bill. Segments are metered, not messages, so trimming the copy is often the biggest saving available. Ready swaps curly quotes, long dashes and ellipses for plain characters before sending, so those don't inflate the count.
Registration adds a fixed cost: $25 at submit for the first month, then $25/mo for registration + $2 per number each month. Replies you receive are billed like sent texts, so budget for conversation volume as well as outbound volume.
For honesty's sake: raw carrier APIs like Twilio (around $0.0083 per segment) and GoHighLevel's LeadConnector (around $0.0083 per message, roughly $0.0128 all-in) cost less per message than Ready Standard. What you get with Ready is self-serve registration, the compliance stack and the platform (inbox, contacts, campaigns, automations) included. See pricing for the current card.
Meta charges per template message. The price depends on the template category (marketing, utility, authentication) and the recipient's country, and Meta changes it periodically. Check Meta's current rate card instead of trusting a number in a blog post. Most businesses also pay a WhatsApp solution provider on top. Free-form replies inside the 24-hour customer window are typically cheaper than business-initiated marketing templates.
When you compare costs, divide by people reached, not by messages attempted. A cheaper per-message channel that reaches a third of your list costs more per reached customer than it first appears.
The rich-messaging gap, and where iMessage fits
Most marketers who consider WhatsApp want a better-looking message: the business name and photo, typing indicators, and a thread that doesn't look like a spam text. In the US, a large share of phones are iPhones, and iMessage already lives there.
Ready's blue line sends texts as iMessage, so they appear blue on iPhones with your business name and photo. It needs no 10DLC registration, so you can start as soon as the line is set up. Texts to Android phones go out from your regular number, so nobody on your list is unreachable. They bill at the regular SMS price if your account already had a number; if the blue line came with its green number, your account's texts bill at 6 cents a segment once you register or send through GoHighLevel. Replies, reactions, typing indicators and group chats land in the same inbox thread as SMS.
The blue line has firm limits:
- Price: $99 a month per line, plus 6 cents a segment sent. Replies are also 6 cents a segment, and reactions are free.
- New conversations: up to 50 per line per day, or roughly 1,500 a month per line if you use the full allowance every day. Texting people you already talk to is unlimited.
- Before a reply: up to 2 texts to someone, and photos only after they reply.
- Not for campaigns: bulk campaigns and drip campaigns send from regular numbers, not the blue line.
The blue line doesn't replace bulk SMS. Use it for one-to-one conversations where the branded look matters, such as sales follow-up, high-value leads and VIP customers, while campaigns go out over registered SMS. It is also not Apple Messages for Business: a blue line can text first. Setup details are in the blue line guide, and platforms can drive it through the blue line API.
RCS is the other rich-messaging option people ask about, and it's still rolling out unevenly across US carriers and devices. We compare it with 10DLC and toll-free in 10DLC vs toll-free vs long code vs RCS. This post doesn't treat it as a Ready send channel.
When WhatsApp is the right call
WhatsApp is worth running if:
- A meaningful share of your customers live outside the US, or are US residents who keep in touch with family abroad.
- Your customers already message you there and say they prefer it.
- You send long-form support content (documents, catalogs, button menus) to people who start the conversation.
In those cases, run WhatsApp alongside SMS, not instead of it. SMS stays the fallback for everyone else, and for anything time-sensitive, like reminders and delivery notices, where reaching every recipient matters. For a broader look at messaging apps against texting, see SMS vs Messenger and WhatsApp for business.
The practical takeaway
For a US audience, bulk campaigns belong on registered SMS. It reaches the whole list, the opt-in rules are clear, and the cost is easy to predict once you understand segments. Add the blue line where a branded, iMessage-native conversation is worth $99 a month per line. Add WhatsApp only if your own customers tell you they live there.
To test the SMS side, sign up, put a card on file and use your first 20 free one-to-one texts before you pay for registration. Campaigns are billed from the first text. Once your brand and campaign are approved, send a small segment of your list and check delivery and replies before scaling up.