Why does one text cost two SMS parts?

Why do I pay for more than one text?

Twilio bills each SMS part. Your phone can join them into one text. What you see on screen is not the paid count.

A plain GSM-7 text with 161 units needs two parts. It puts 153 units in the first and 8 in the next. Send it to 1,000 people and you use 2,000 parts. The rate from your provider sets the cost.

Source: Twilio: SMS limits, segment billing and toll-free exceptions

Is the limit 160 or 70?

GSM-7 is the format for common letters and symbols. It fits 160 units in one part. A longer text fits 153 in each part. The spare space tells the phone how to join them.

Unicode lets you use more symbols. Twilio calls this format UCS-2. It fits 70 units in one part, or 67 per part for long texts. One mark on the screen can use more than one unit.

Source: Twilio: why Unicode changes SMS length

Why does one emoji change the count?

An emoji makes the whole text use Unicode. It does more than take space at the end. Curly quotes can cause this switch too.

The first sample below uses one part. Add a smile and it uses two. The words, link and STOP line stay the same. Try both in the SMS counter.

Source: Twilio: why Unicode changes SMS length

Does an emoji count as one?

Not always. Our counter uses UTF-16 units for Unicode text. In that count, 😄 uses two units. Some emoji join many marks into one picture. They use even more space.

Some plain symbols use extra space too. A bracket or brace uses two GSM-7 units. That is why a word app may give a different count. Paste your text into an SMS counter to check.

Sources: Twilio: GSM-7 symbols that take two units · MDN: UTF-16 units and emoji

What should I paste into the counter?

Use the text the shopper will get. Keep the store name, full link and line that tells them how to stop texts. Spaces and line breaks count too.

Swap a name field for a sample name. Try a long one too. “Hi Jo” needs less room than “Hi Christopher.” If your app changes links, count the link it will send. Check again after edits.

Why might my provider show a different count?

Twilio has a tool called Smart Encoding. When on, it can change some curly quotes and long dashes to plain ones. That can lower the count. It does not change every symbol. Check your settings and sent-text log.

The sending number can matter too. For long texts from toll-free numbers to the US or Canada, Twilio lists 152 GSM-7 or 66 Unicode units per part. Picture messages, WhatsApp and RCS use other rules.

Sources: Twilio: characters changed by Smart Encoding · Twilio: SMS limits, segment billing and toll-free exceptions

How can I use fewer parts?

Cut extra words first. “We just wanted to let you know your cleanser is still in your cart” can be “Your cleanser is still in your cart.” Keep the item, the reason to write and the next step.

Then check spare emoji and symbols. Keep names and languages correct. Keep the store name and STOP line. Two clear parts can be more useful than one confusing part.

What should I check before a send?

Use the counter to compare drafts. It does not send a text. Once you pick one, send yourself a test through your provider. Open the link on your phone. Check the parts in the sending log.

For a larger send, multiply the parts by the number of people. Check how many your plan covers and the cost of more. Do this before sending to the full list.