How to Send Bulk Text Messages to Customers

🔑 Key Takeaways:

  • Bulk SMS requires prior express written consent from each recipient—texting a purchased list without consent is both a TCPA violation and a fast track to carrier blocking
  • Message quality matters more in SMS than in email because the inbox is more personal and space is limited—unclear or irrelevant texts generate opt-outs, not engagement
  • 10DLC (10-digit long code) registration is now required for business SMS in the US—unregistered numbers face delivery filtering by carriers

Bulk SMS is one of the most direct customer communication tools available to businesses. A text message is more likely to be seen than an email, faster to deliver than a mailing, and cheaper than a phone call. But it's also the most personal of the three—your message lands in the same place as texts from the customer's family and friends. That proximity demands respect for both the channel and the person receiving it.

Here's how to do bulk SMS right, from setup through measurement.

Step 1: Choose Your SMS Platform

The right platform depends on your volume and use case:

Feature to Check Why It Matters
10DLC registration support Required for US business SMS; platforms that don't support it will see your messages filtered or blocked
STOP/HELP keyword automation TCPA requires honoring opt-outs immediately; manual processing at scale is impossible
Delivery reporting Know which messages delivered, which bounced, and which resulted in opt-outs
Personalization / dynamic fields First-name personalization alone improves engagement meaningfully
Contact list management Ability to segment, tag, and suppress contacts without manual CSV management
Two-way messaging Customers who reply should get a response—either automated or routed to a human

Step 2: Build a Compliant Contact List

The list is the foundation of every bulk SMS campaign. A purchased list almost never meets TCPA consent requirements for automated text messages. Build your list through:

  • Website opt-in forms: Checkbox explicitly saying "I agree to receive text messages from [Business Name]" with the number to expect texts from
  • Keyword opt-in: "Text JOIN to 555-555-1234 to receive updates and offers from [Business]"
  • Point-of-sale collection: Phone number collected at checkout with clear SMS consent language—not buried in general terms
  • Existing customers with SMS consent: Customers who already have a relationship with your business and have separately opted in to SMS communications

Step 3: Write Messages That Get Read

Good bulk SMS messages share four characteristics:

  1. Identify yourself immediately: Start with your business name. "Hi Sarah, [Business Name] here:" removes any ambiguity about who's texting before the recipient reads further.
  2. State the purpose in the first line: Get to the point. What do you want them to know or do? The first sentence should answer that question.
  3. Include one clear action: A link, a reply keyword, a phone number to call. Not three options—one. More choices = fewer actions taken.
  4. Include opt-out instructions: "Reply STOP to unsubscribe" is legally required and builds trust by demonstrating respect for the recipient's inbox.
Example: Retail Flash Sale SMS

"Hi Sarah, River St. Boutique here: Our summer clearance starts TODAY—40% off all dresses in-store and online through Sunday. Shop now: [LINK] Reply STOP to unsubscribe."

Business identified. Purpose clear. Single action. Opt-out included. 144 characters.

Step 4: Send at the Right Time

TCPA restricts automated text messages to between 8 AM and 9 PM in the recipient's local time zone—same rule as automated calls. Within that window, timing affects engagement:

  • Retail and promotions: Tuesday–Thursday, 10 AM–2 PM or 6–8 PM performs best
  • Appointment reminders: 24–48 hours before the appointment, delivered in the late morning
  • Flash sales or time-sensitive alerts: immediate send when the offer activates
  • Avoid Monday mornings (inboxes are full) and Sunday evenings (feels intrusive)

Step 5: Measure and Optimize

The metrics that matter for bulk SMS:

  • Delivery rate: What percentage of messages were successfully delivered (not bounced or filtered)
  • Click-through rate: For messages with links, how many recipients clicked
  • Opt-out rate: How many replied STOP; rising opt-out rate signals message fatigue or relevance issues
  • Conversion rate: How many completed the intended action (purchase, appointment booked, form submitted)

Send Your First Bulk SMS Campaign Today

Robotalker makes bulk text messaging simple—upload your list, write your message, and reach thousands of customers in minutes with built-in compliance tools.

  • ✔️ 10DLC registration support
  • ✔️ Automatic STOP/HELP opt-out processing
  • ✔️ Real-time delivery reporting
Start Free Trial →

FAQ: Bulk Text Messaging

Only for certain non-marketing messages. Under TCPA, prior express written consent is required for automated marketing texts to cell phones—this applies even to existing customers. However, transactional texts (appointment reminders, order confirmations, delivery notifications) to customers who gave you their number as part of a transaction may qualify under the "prior express consent" standard, which is slightly less strict than the written consent standard for marketing. When in doubt, get explicit SMS consent. It protects you legally and builds a better list—people who opted in specifically to SMS engage more than those who didn't.

Long codes (10-digit local numbers, 10DLC) are the standard for most business SMS today—they look like a regular phone number, support two-way messaging, and are the most affordable. Short codes (5-6 digit numbers like 55555) handle very high volume and have the highest throughput but cost $1,000–$1,500/month to lease and require a longer registration process. Toll-free numbers (800, 888 prefixes) can be used for SMS with registration and are a middle ground—more recognizable than a random local number, cheaper than a short code. For most small and mid-size businesses, 10DLC is the right starting point.

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