Yes. You can use an SMS API to send one message or ten thousand, in the same request structure. Here’s how it actually works, and what to check before you send.
Bulk SMS vs an SMS API
This is worth clearing up first, because there are a lot of terms and acronyms used in the SMS – or even communication – world.
Bulk SMS usually means logging into an online platform, uploading a list of contacts, and sending a campaign. This is built for marketing teams, business owners/teams or any business that just needs to send a quick, non-code way to send a text message.
An SMS API means your system (such as a CRM) talks directly to the SMS system. You send an HTTP request, and the SMS system sends the texts. It’s built for developers, and it triggers automated, high-volume messaging – order confirmations, reminders, alerts, campaigns triggered from your own database.
Both can send bulk volumes. The difference is who’s doing the sending – is it a person clicking buttons, or your system making a call? Is the message being sent all in one go, or is it triggered depending on a customer’s behaviour?
Why use the API instead of just logging in and sending?
Fair question. If you’ve got a one-off list and a spare ten minutes, a web platform is easy up front. The API earns its place when the campaign needs to connect to something else you’re already running, such as:
Your CRM
Trigger a text the moment a lead status changes, a deal closes, or a contract’s about to renew, without anyone manually exporting a list.
Your booking system
Send a batch of reminders every morning for tomorrow’s appointments, pulled straight from the calendar.
Your ecommerce platform
Text everyone with an item back in stock, generated from a live inventory feed.
Your internal database
Segment and message customers based on criteria only your system knows, like usage, spend, or renewal date.
A scheduled job
Run the same campaign logic every week without a person doing it by hand each time.
Hopefully you get the idea. The API is for messages that are triggered by data, not by someone deciding today’s the day to send. If the list or the timing depends on something already happening in one of your systems, that’s the API’s job.
How bulk sending works through an API
Instead of one request per message, you send a batch. One API call containing a list of recipients and message content. You can either:
- Send the same message with the same content to every recipient – a straightforward broadcast, or
- Personalise each message by pulling in a name, order number, or appointment time per recipient, all in the same batch
You don’t need to loop through recipients one at a time in your own code. The batch endpoint handles that for you.
What you need before you send
A list of numbers
UK format (‘07900123456’) or international (‘447900123456’) – no leading ‘+’.
Consent
If it’s a marketing message, UK rules require express opt-in and a clear way to opt out on every message you send. Transactional messages – such as order updates, appointment reminders, OTPs – don’t carry the same marketing restrictions, but you should still only be texting people who expect to hear from you.
A sender ID
UK networks now restrict what you can set as your sender name, to cut down on fraud and scam texts. If you want to use a recognised brand name that isn’t yours, you’ll need a letter of authorisation. Otherwise your text gets blocked before it ever reaches a handset.
What it costs
This is where bulk sending gets expensive with the wrong provider. Most SMS companies charge you for every message submitted, whether it’s delivered or not. That can add up on a large campaign, as undelivered texts typically account for close to 10% of wasted spend.
We only charge for messages that are actually delivered. Failed sends are refunded automatically. On a batch of 10,000, that’s a big difference. You can see our pricing page for the most up to date information.
After you send
Every batch generates a delivery report – a breakdown of what happened to each message, including any of our 25 error codes explaining exactly why a text didn’t land.
Getting started with the SMS API
1. Sign up for a free account – you get 50 free credits to test with
2. Generate your API key
3. Send a small test batch to confirm formatting, sender ID and delivery before you send at scale
4. Check the API reference docs for the current batch endpoint and field names
No contract, no setup fee, no minimum order. Just an API key and a list of numbers.
Create your free API key and send your first batch today.