Sending your first bulk SMS campaign is exciting — but getting it wrong can be expensive, damage your brand, or land you in trouble with the ICO. Here are five things every business should understand before pressing send.
1. Consent Is Not Optional
Under UK PECR regulations, you must have explicit opt-in consent before sending marketing SMS. This means:
- Recipients must have actively agreed to receive texts from you (not just given you their number)
- Pre-ticked boxes on forms don't count as consent
- Purchased contact lists almost never include valid consent — don't use them
- You must keep records of when and how each person consented
The only exception is the "soft opt-in" for existing customers, where you can message about similar products if they were given the chance to opt out when their number was collected. Read more about compliance in our anti-spam policy.
2. Character Count Affects Cost
A single SMS holds 160 characters in standard GSM encoding. Exceed this, and your message splits into multiple segments — each charged separately:
- 1 segment: Up to 160 characters (GSM) or 70 characters (Unicode)
- 2 segments: Up to 306 characters (GSM) or 134 characters (Unicode)
- 3 segments: Up to 459 characters (GSM) or 201 characters (Unicode)
Emoji, accented characters, and smart quotes from Word trigger Unicode encoding, halving your character limit. A 150-character message with one emoji becomes 3 segments instead of 1.
3. Your Sender ID Matters
Your sender ID is what recipients see as the "from" name. For business SMS, you typically want an alphanumeric ID showing your brand name (e.g., "FareText"). Things to know:
- Alphanumeric IDs are limited to 11 characters
- Recipients cannot reply to alphanumeric sender IDs — they're one-way only
- If you need replies, use a numeric sender ID (a virtual mobile number)
- Some countries require sender ID registration — check requirements for international messaging
4. Timing and Frequency Make or Break Your Campaign
Research shows that optimal SMS marketing windows are:
- Best times: Tuesday to Thursday, 10am-12pm or 2pm-4pm
- Acceptable: Monday to Saturday, 9am-8pm
- Avoid: Before 8am, after 9pm, and Sundays
- Frequency: 2-4 messages per month maximum from any single brand
Over-messaging is the number one reason people unsubscribe from SMS lists. Less is genuinely more.
5. Choose Your Provider Carefully
Not all SMS providers are equal. The differences that matter:
- Direct carrier connections vs grey routes: Direct routes (used by Faretext) guarantee delivery and reporting. Grey routes are cheaper but unreliable
- UK-based support: When something goes wrong with a campaign, you need responsive, knowledgeable help — not an overseas call centre
- Delivery reporting: You should know exactly how many messages were delivered, not just how many were sent
- Compliance tools: Automatic opt-out handling, suppression lists, and consent management
Ready to Send?
With these fundamentals covered, you're ready to launch your first campaign. Faretext offers multiple ways to send bulk SMS — through our SMS API, the Oello web platform, or Email to SMS. Every new account receives complimentary credits to test the platform. Connect with us today.
