A long SMS can be billed as several message parts even when a phone displays one conversation bubble. Use PD Twilio SMS’s Count segments before sending, and treat it as a length estimate rather than a final currency quote.

Measure the message

1. Open PD Modules → Twilio SMS → Send SMS.
2. Enter the intended text, or fill the composer from a template and review it.
3. Choose Count segments.
4. Review the encoding and segment count, then edit and count again if necessary.

This preview does not send an SMS. Keep the intended recipient and Send via choice under review before using the separate Send SMS action.

Why a short message can become several parts

For GSM-7 text, the usual single-part capacity is 160 units. Longer messages use 153 per part because multipart information takes space. Characters from the GSM extension set, including braces and the euro symbol, consume extra units.

Unicode messages normally have a single-part capacity of 70 units and multipart capacity of 67. An emoji can use more than one unit. Adding one character outside the GSM alphabet can therefore change the encoding and increase the count for the whole message. These limits are described in Twilio’s SMS character guidance.

Keep the estimate useful

Count the actual intended wording, including links and personalised values, rather than an empty template. A longer customer name or ticket subject can change the final message length. For campaigns, the preview estimates audience and segments; personalised messages and provider processing can change the final billed total.

Shorten unnecessary wording without removing the reason for the text or the action the recipient needs. Do not split one meaningful notice into repeated manual sends just to reach a displayed count. Twilio charges vary by destination and sending setup; the module’s segment count is not a guaranteed monetary charge.

Check Twilio-specific differences

The module’s preview uses the usual GSM-7 and Unicode capacities. Twilio uses 152 and 66 units respectively for multipart toll-free SMS to US or Canadian destinations, so the preview can understate those message parts. A Messaging Service’s Smart Encoding can also replace some punctuation and change the final encoding. Neither case is a reason to treat the preview as a final invoice.

Review the actual provider message record for the sent text and segment count. For a Messaging Service, the initial provider segment count can be zero before a sender has been assigned. Compare the later result rather than interpreting that initial zero as a free message.

See the PD Twilio SMS WHMCS guide for related tasks, or explore PD Twilio SMS.