Why Is My Twilio Bill So High? (The Hidden Cost of a Single Character)

We’ve all been there. You open your monthly invoice, expecting the usual number, and your jaw hits the floor. The bill from Twilio has tripled. Panic sets in. Did we get hacked? Did we accidentally text the entire population of France? Why is my Twilio bill so high?

I recently helped a client troubleshoot this exact nightmare. Their SMS bill had skyrocketed from one month to the next, yet their volume hadn’t changed. They were sending the same number of messages to the same size audience.

The culprit wasn’t a hacker or a glitch. It was a bullet point.

Specifically, this character: •

Here is why a single formatting choice can secretly double or triple your messaging costs, and how you can fix it today.

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The “Anatomy” of a Text Message

To understand why your bill exploded, you have to understand how carriers count text messages. We tend to think of one text as “one thought,” but carriers think in Segments.

In the standard world of SMS, a single segment is 160 characters.

If you send a message that is 165 characters long, you aren’t charged for one message; you are charged for two segments. Most of the time, this math is predictable. You write your copy, keep it under 160 (or 320 for two segments), and hit send.

But there is a trap door, and it relies on which alphabet you use.

The Two Alphabets: GSM-7 vs. Unicode

SMS networks were built in the 1980s. To save data, they created a standard alphabet called GSM-7. It includes:

• Standard letters (A-Z)
• Numbers (0-9)
• Basic punctuation (., ?, !, @)

As long as you stick to these boring, standard characters, you get your full 160 characters per segment.

However, modern marketers love emojis, fancy formatting, and special symbols. The moment you introduce a character that isn’t in that 1980s alphabet, like a bullet point (•), a curled “smart quote” (”), or a taco emoji (🌮), the entire message system changes gears.

To support that one fancy character, the messaging system switches the entire message to a different encoding standard called Unicode.

The Math of the Price Hike

Here is the kicker: Unicode characters take up much more data space. Because of this, the character limit for a Unicode message drops drastically.

• Standard (GSM-7) Limit: 160 characters per segment.
• Unicode Limit: 70 characters per segment.

Let’s look at the math from my client’s situation. They were sending a promotional text that was roughly 240 characters long.

Scenario A: Using a hyphen (-) A hyphen is a standard GSM-7 character.

• Limit: ~153 characters per segment (when messages are long and linked together).
• 240 characters ÷ 153 = 2 Segments.

Scenario B: Using a bullet point (•) The bullet point forces Unicode.

• Limit: ~67 characters per segment (when linked).
• 240 characters ÷ 67 = 4 Segments.

By changing a hyphen to a bullet point, they doubled the number of segments required to send the exact same text. Double the segments means double the bill.

Are You leaking Money? Check for These “Gotchas”

It isn’t just bullet points. If your bill is high, check your recent message templates for these common Unicode triggers:

1. Smart Quotes: If you copy-paste your text from Microsoft Word or Google Docs, your standard quotation marks (") might automatically convert to curled “smart quotes” (”). Smart quotes trigger Unicode.
2. Emojis: Even a single smiley face forces the whole text into Unicode. This is often worth the cost for engagement, but be aware of the price tag.
3. Long Dashes: The em-dash (—) is different from a hyphen (-). The em-dash is Unicode.
4. Non-English Characters: Accents like ñ, ç, or ü are usually not supported in standard GSM-7 (though some rare exceptions exist depending on the carrier, it’s safer to assume they trigger Unicode).

The Fix for Why Is My Twilio Bill So High?

The solution is incredibly simple: Sanitize your text.

If you are seeing a spike in costs, audit your SMS templates. Replace the “fancy” characters with their boring cousins:

• Replace • with - or *
• Replace “ and ” with "
• Replace — with --

It’s a small change that your customers won’t notice, but your finance department definitely will.