Almost everyone in Sri Lanka has a mobile phone, and almost everyone reads an SMS. That makes bulk SMS one of the quickest ways to reach customers: no app to install, no internet connection needed, and messages are usually read within minutes. This guide explains how businesses use bulk SMS well, and the mistakes that waste money or annoy customers.
What is bulk SMS?
Bulk SMS means sending the same text message to many phone numbers at once, or sending automatic messages from your website or business system. Instead of typing messages on a phone, you use an SMS service or gateway that sends them for you, and you can personalise each one, for example with a customer's name or an order number.
Four ways businesses use bulk SMS
1. Promotions and announcements
Tell customers about an offer, a new product, a sale, or a change in opening hours. Promotional messages work best when they are short, clear, and sent to people who asked to hear from you.
2. Order, delivery, and payment alerts
An automatic message when an order is received, shipped, or paid keeps customers informed and cuts down calls asking "where is my order?". If you run an online store, this is one of the most useful messages you can send. See how to start selling online with PayHere.
3. One-time passwords (OTP)
Login and verification codes sent by SMS help protect customer accounts. Good practice is a short code that expires quickly, can be used only once, and limits how many times it can be requested.
4. Appointment and payment reminders
A short reminder the day before reduces missed appointments and late payments. Clinics, salons, schools, service businesses, and anyone who bills regularly use these.
How long can an SMS be?
A standard SMS holds 160 characters. Messages written in Sinhala or Tamil use Unicode characters, so each message holds fewer, about 70 characters. Longer messages are split into several parts, and each part holds slightly fewer characters (about 153 for English and 67 for Unicode). You may be charged per part, so short messages save money and are easier to read.
Writing a good SMS
- Say who you are at the start, so the customer knows who it is from
- Put the key information first, such as the offer, the code, or the time
- Keep it short: one message, one purpose
- Include a clear next step: a phone number to call, a short link, or a date
- Avoid all capitals and too many symbols, which look like spam
- Use the customer's language: English, Sinhala, or Tamil, whichever they use
Consent, opt-out, and timing
- Only message people who agreed to hear from you. Buying or collecting random numbers damages your reputation and annoys customers.
- Give people a way to opt out, and honour it quickly.
- Send at sensible times, not late at night or very early in the morning.
- Do not send too often. A few useful messages a month work better than daily offers.
- Follow the rules. Mobile operators and regulators may have requirements about promotional messages, sender names, and sending hours. We advise on current requirements when we set up your service.
Sender name
Many SMS services can show your business name as the sender instead of a phone number, which helps customers recognise you. What is allowed depends on the mobile operators, so it is worth asking about it when you set up the service.
Sending automatically from your website
An SMS gateway lets your website, online store, or business software send messages automatically, for example an order confirmation the moment a customer pays, or an OTP when someone logs in. Tell your provider what system you use, and they can advise how to connect it.
Common mistakes
- Sending promotions to numbers that never agreed to receive them
- Writing long messages that split into several parts
- Forgetting to say who the message is from
- Sending at night, or too many messages in a short time
- Using SMS for something that needs a long explanation, where an email or a call is better
- Not testing messages on a real phone before sending to a whole list
Measuring results
Track what happens after a campaign: how many calls, visits, or orders it brought, and how many people asked to opt out. Compare different wording or send times, and keep what works.
SMS or email?
SMS is best for short, time-sensitive messages that need to be read quickly. Email suits longer content, newsletters, and invoices. Many businesses use both: SMS for alerts and reminders, and email for newsletters. Read bulk email deliverability: SPF, DKIM, and DMARC to make sure your emails reach the inbox.
Frequently asked questions
Can I send bulk SMS in Sinhala and Tamil?
Yes. Sinhala and Tamil messages use Unicode, so each message part is shorter than an English message. Keep them brief.
Do customers need an app or internet to receive SMS?
No. SMS works on any mobile phone with signal, which is why it reaches customers who are not online.
Can I send SMS automatically when a customer places an order?
Yes, through an SMS gateway connected to your website or system. The message goes out automatically when the order is placed or paid.
How much does bulk SMS cost?
It depends on how many messages you send and the type of message, so ask for a written quotation based on your expected volume.
Is SMS better than WhatsApp?
They do different jobs. SMS reaches everyone with a phone number, with no app needed. WhatsApp suits conversations with customers who already use it. Many businesses use both.
Get bulk SMS set up for your business
We provide bulk SMS solutions and SMS gateways for Sri Lankan businesses. See our bulk SMS service, our bulk email servers, our wider server and cloud solutions, or contact us for a written quotation.