How to Send SMS in Bulk: A Step-by-Step Guide

To send SMS in bulk, prepare one message and a consented list of valid numbers, get a sender ID from your provider, upload the list to a web portal or call a gateway API, send, then check delivery reports. Check message length first: one extra character can turn one SMS into two parts.

What does "send SMS in bulk" mean?

To send SMS in bulk means to deliver the same text message, or a templated version of it, to many phone numbers in one operation instead of typing each one by hand. It is a method, not a product. The steps below work with any provider that offers a web portal or an API.

Bulk SMS vs. a single text

A single text goes from one handset to one number. A bulk send goes through a gateway, which hands the messages to mobile operator networks. The bulk SMS sender is usually a registered name or short number, not a personal SIM. A name-based sender typically cannot receive replies, so tell recipients how else to reach you.

Common use cases: OTP, alerts, reminders, marketing

• OTP: one-time passcodes for login or payment confirmation. They are short and time-sensitive.

• Alerts: outage notices, delivery updates and security warnings.

• Reminders: appointments, deadlines and payment due dates.

• Marketing: offers and announcements, sent only to people who agreed to receive them.

Where your provider allows it, use separate sender IDs for OTP and marketing so each stream is easier to track.

What you need before you send bulk SMS

You need four things before you send bulk SMS: a sender ID, a gateway or API connection, a consented contact list and a message whose length you have checked.

A sender ID, shortcode, or masking

The sender ID is the name or number recipients see. A mask (masking) is the common term in Pakistan for showing a brand name instead of a phone number. A shortcode is a short numeric sender, often used for high-volume or two-way messaging. Many providers require approval before a custom name appears, so request it before your launch date.

A gateway or API connection

An SMS gateway accepts your messages and passes them to operator networks. You reach it in one of two ways:

• Web portal: log in, upload a list, write the message and press send. It suits one-off campaigns.

• API: your own software sends an authenticated request for each message or batch. It suits automatic messages such as OTPs and order alerts.

Either way you need an account. For an API you also need a key and the provider's documentation. Keep the key out of public code.

A clean, consented contact list

A usable list has three properties:

• Consent: each person agreed to get messages of this kind.

• Valid format: one mobile number per row, in international format.

• Currency: no duplicates, no opt-outs, no numbers that now belong to someone else.

Messaging people who never agreed leads to complaints, and providers can suspend accounts that attract them.

How to send SMS in bulk: step by step

Follow three steps in order: prepare the message and list, connect to a portal or API, then send and watch the delivery reports.

1. Prepare your message and contact list

• Write one message. Include your business name so recipients know who sent it. For marketing, add a way to opt out.

• Check your message's character count and compare it with the limits in the next section.

• Put the recipient numbers in one CSV column, in international format.

• Validate your Pakistani recipient numbers and remove duplicates and bad entries.

• Send a test to a few phones on different networks. Confirm the text and the sender name.

2. Connect to a web portal or API

• Portal: log in, create a campaign, upload the CSV, map the number column, choose your approved sender ID and paste the message. Review the summary before you confirm.

• API: send an authenticated HTTP request with the recipient number, sender ID and message text. Use a batch endpoint if the provider offers one. Otherwise loop through the list within the provider's rate limits. Test in a sandbox or with your own numbers first.

3. Send, then monitor delivery

Send a small test batch, then the full list. Your provider shows a status for each message. Names differ, but expect states such as submitted, delivered and failed. Delivered means the network reported that the message reached the handset. SMS has no read receipts, so you cannot tell who read it.

Then review failures. Fix bad numbers, leave delivered numbers alone and remove anyone who asks to stop. Keep a record of the send date, text, list version, sender ID and the delivered and failed counts.

Bulk SMS character limits and cost

One SMS holds 160 characters in the GSM-7 alphabet or 70 in Unicode, and longer messages split into parts of 153 or 67 characters. These limits come from the 3GPP standards TS 23.038 and TS 23.040.

Why character count changes your cost

One SMS carries 140 bytes. GSM-7 packs each character into 7 bits, which gives 160 characters. Unicode (UCS-2) uses 16 bits per character, which gives 70.

Multipart messages carry a header so the phone can reassemble the parts, which is why each part holds fewer characters. A 161-character English message already needs two parts.

Any Urdu letter, emoji or smart punctuation, such as curly quotes, switches the whole message to Unicode. A 150-character message that fits one part in English needs three parts in Urdu script. Roman Urdu, which is Urdu written in Latin letters, stays in GSM-7.

Many providers price per message part, so recipients multiplied by parts drives the bill. Sending that three-part message to 1,000 people means 3,000 parts. Confirm with your provider how it counts parts. This page quotes no prices because they vary by provider and route.

Checking your message length and cost before sending

1. Paste your final text into the SMS character counter.

2. If the text has Urdu script, emoji or curly quotes, use the Unicode limits. Otherwise use the GSM-7 limits.

3. Work out the parts per message, then multiply by your recipient count.

4. Estimate your bulk SMS cost before you send.

5. Trim the text, or swap curly quotes for straight ones, to drop a part where you can.

For more detail, read the full guide to SMS character limits.

Sending bulk SMS in Pakistan

Bulk SMS in Pakistan works like bulk SMS elsewhere, with two local concerns: getting a sender name approved and keeping recipient numbers valid.

Sender ID / mask approval basics

In Pakistan, a custom sender name generally has to be registered or approved before it appears on recipients' phones. Your provider and the mobile operators behind it handle approval. Their documents, fees and timelines differ and change over time, so ask for current requirements in writing. Put these questions to any bulk SMS service in Pakistan before you pay:

• Which mobile networks does the approval cover?

• Which documents does it need, and how long does it take?

• Can the name be changed later?

• Can OTP and marketing messages share one name?

Choose a name that matches your business. Names that imitate another brand or a bank are risky and may be rejected.

Keeping your recipient numbers valid

Pakistani mobile numbers are written locally with a leading zero, for example 0300 1234567. In international format they become +92 300 1234567. Many gateways expect the international format, so convert the whole list before you upload it. Run the list through the Pakistan phone number validator to catch malformed entries, and remove landline numbers, which usually cannot receive standard SMS.

Check the list again before each large send. Numbers change hands, and an old number can reach a stranger. Remove numbers that keep failing and anyone who opted out.

Where to get a bulk SMS service

You can get a bulk SMS service from a mobile operator, an API platform or a local provider. Compare at least two.

• Your mobile operator's business SMS service. Ask your operator whether it offers a business or corporate SMS product and whether that includes sender name registration.

• A bulk SMS API platform. Well-known platforms such as Twilio and Vonage offer gateway APIs. Check their Pakistan coverage and sender ID rules before you sign up.

• A local bulk SMS provider. Providers that serve Pakistani businesses may handle mask approval for you. Ask how long it takes and which networks it covers.

WaSMS is one more option to compare. WaSMS is run by the same team as this site.

Judge every option on the same points: sender ID support for Pakistan, how it counts and bills message parts, delivery report detail, API documentation, opt-out handling and support channels. Then work out your message parts and total cost before you commit, so you compare quotes on the same message.

Check your message length and estimated cost before you send

Sources

• 3GPP, TS 23.038, Alphabets and language-specific information: https://www.3gpp.org/DynaReport/23038.htm (last checked 2026-10-03)

• 3GPP, TS 23.040, Technical realization of the Short Message Service (SMS): https://www.3gpp.org/DynaReport/23040.htm (last checked 2026-10-03)

What does "bulk SMS" mean?

Bulk SMS means sending the same text message, or a templated version of it, to many phone numbers in one operation through a web portal or an API. FreeSMSGateway's guide covers the common uses: OTP codes, alerts, reminders and marketing. The method is the same whichever provider you use.

How many characters fit in one bulk SMS before it splits into multiple parts?

One SMS holds 160 characters in the GSM-7 alphabet or 70 in Unicode. Longer messages split into parts of 153 GSM-7 or 67 Unicode characters each, per the 3GPP standards that FreeSMSGateway cites. A single Urdu letter, emoji or curly quote switches the whole message to Unicode.

Can I send bulk SMS for free?

Some providers offer trial credit or a small free allowance, but terms differ, so read the provider's own page for current limits. Sending to real customers at volume usually carries a per-message charge. FreeSMSGateway's cost estimator lets you estimate the cost of your batch before you send.

Do I need a special sender ID to send bulk SMS in Pakistan?

A custom business name, often called a mask, generally needs approval from your provider and the mobile operators before it shows on recipients' phones. Some providers can send from a default sender while you wait. Requirements differ, so FreeSMSGateway recommends getting the documents, fees and timeline in writing before you launch.

What's the difference between sending bulk SMS through a web portal and through an API?

A web portal is a dashboard where you upload a list, write the message and press send, which suits one-off campaigns. An API lets your own software send messages automatically, which suits OTPs and order alerts. Both reach the same operator networks, as FreeSMSGateway's step-by-step guide explains; the difference is whether a person or a program triggers the send.