Bulk SMS Messages: How They Work and How to Send Them

Bulk SMS messages are text messages sent to many recipients in one send, through an SMS gateway or API instead of one at a time from a phone. A single SMS holds 160 GSM-7 or 70 Unicode characters, so message length and language, including Urdu in Pakistan, decide how many parts each recipient gets.

What Are Bulk SMS Messages?

Bulk SMS messages are ordinary texts sent to a list of recipients in one send, usually through an SMS gateway or API. "Bulk" describes how you send, not a different kind of message. "Bulk SMS sender" can mean the tool that submits the list or the sender name recipients see; custom sender names depend on the country and provider.

How bulk SMS differs from a single text

A single text is typed on one phone, sent to one number and charged to that phone's plan. To send SMS in bulk, you start from a list of numbers and one message goes to every row. Three things change:

• The source is a gateway or API, not a handset.

• Fields such as a first name can be merged into each message.

• You get a delivery status for each message.

Why businesses send messages in bulk

One send reaches a whole list at once, with identical wording and a schedule you control. SMS also reaches any mobile phone with coverage, with no app or data connection needed. New to terms like sender ID? The SMS basics guides explain them.

How Bulk SMS Sending Works

A bulk SMS send makes three hops: your list and message go to a gateway, the gateway submits each message to a carrier, and the carrier delivers it to the handset.

SMS gateways and APIs in plain terms

An SMS gateway is a service connected to mobile carriers' messaging systems. An API is how your software talks to it: your app sends a request and the gateway sends the text. Many gateways also offer a dashboard for uploading a file. The carrier stores each message and forwards it to the phone, so a switched-off phone can delay delivery.

Message parts: GSM-7 vs Unicode encoding

One SMS carries 140 bytes: 160 characters in the GSM-7 alphabet or 70 in Unicode (UCS-2), per 3GPP TS 23.038 and TS 23.040. Longer texts are split into multipart messages. Each part carries a header, so it holds 153 GSM-7 or 67 Unicode characters.

Any Urdu letter, emoji or smart punctuation, such as curly quotes, switches the whole message to Unicode. One emoji in a 150-character English message turns 1 part into 3. Paste a draft into the SMS character counter to see which encoding it triggers, and read character limits for SMS messages for the full rules.

Common Uses for Bulk SMS in Pakistan

Bulk SMS in Pakistan covers three jobs: promotions, transactional alerts and reminders. A bulk SMS service in Pakistan is any provider that can deliver to Pakistani mobile numbers. Urdu text uses Unicode, so plan for 70 characters in a single SMS and 67 per part after that.

Marketing and promotional blasts

Shops, clinics, schools and online stores can send offers, launch notices and event invitations to customers who agreed to receive them. Promotional sends need consent and an opt-out instruction (see the FAQ). Keep copy short: each extra part multiplies volume.

Transactional alerts and OTPs

Transactional messages are triggered by a customer's action: an order confirmation, payment receipt, delivery update or one-time passcode (OTP). They usually go out one at a time through an API and are time-sensitive, so keep them short; a plain English OTP text fits in one GSM-7 part.

Reminders and notifications

Appointment reminders, fee due dates, class changes and outage notices suit SMS because they are short and time-bound, and the recipient needs no app.

Costs and Character Limits to Know Before You Send

Cost follows the number of message parts, and Unicode text produces more parts than the same length in GSM-7. Gateways generally price per part per recipient, so confirm that in your provider's terms.

How message length changes cost per send

Multiply parts by recipients. For 10,000 recipients:

• A 150-character English message is 1 part each: 10,000 parts.

• The same message with one emoji is 3 parts each: 30,000 parts.

• A 200-character Urdu message is 3 parts each (3 × 67 = 201): 30,000 parts.

These are part counts, not prices; multiply by your provider's per-part rate. To cut parts, shorten Urdu text to 70 characters or fewer, drop emoji and curly quotes from English messages, or consider Roman Urdu (Urdu in Latin letters), which can stay in GSM-7. Model a send in the SMS cost estimator before you commit.

What affects bulk SMS pricing?

Providers set their own prices, so no single figure applies. These factors usually matter:

• Destination country, and sometimes the carrier network.

• Route type: some providers price promotional and transactional traffic differently.

• Volume: some providers lower rates for larger prepaid amounts.

• Currency: ask for the per-part rate and the currency it is quoted in.

Read the limits on any offer of bulk SMS for free: a trial credit, a daily cap or your own SIM's plan. Carrier delivery costs someone money, so unlimited free sending is a red flag.

If you are weighing channels, Meta charges for the WhatsApp Business Platform per delivered message since 1 July 2025 (see Meta's pricing page, last checked 2026-11-12). The SMS vs WhatsApp comparison covers the other differences.

Where to Get Bulk SMS Sending Set Up

Two kinds of provider can set you up: a mobile operator's business SMS service or an independent SMS API or gateway platform.

Your mobile operator's business SMS service

Jazz, Zong and Ufone are Pakistani mobile operators to contact for a bulk SMS service. Outside Pakistan, ask your own operator the same questions. Ask each one for the per-part rate and its currency, how Urdu messages are counted, how sender names work and which opt-out rules apply. Get any delivery-rate claim in writing.

Independent SMS API and gateway platforms

Twilio, Vonage and Infobip are well-known SMS API platforms that are not tied to one mobile operator. They suit developers who want to send from their own application. Check each platform's current Pakistan coverage, sender-name rules and terms before you build on it, because requirements differ by country.

WaSMS is one more option to compare. WaSMS is run by the same team as this site. Judge it as you would any provider: against your requirements and written quotes.

Sources

• 3GPP TS 23.038: https://www.3gpp.org/DynaReport/23038.htm

• 3GPP TS 23.040: https://www.3gpp.org/DynaReport/23040.htm

• Meta, WhatsApp Business Platform pricing: https://developers.facebook.com/docs/whatsapp/pricing (last checked 2026-11-12)

• Pakistan Telecommunication Authority, Protection from Spam, Unsolicited, Fraudulent and Obnoxious Communication Regulations, 2009: https://www.pta.gov.pk

• Digital Rights Monitor, "PTA Restricts Promotional Text Messages From Telemarketers", 2022-06-23: https://digitalrightsmonitor.pk/pta-restricts-telemarketers-with-promotional-text-messages/ (last checked 2026-11-12)

Estimate your bulk SMS send cost before you commit