SMS (or Short Message Service) plays a crucial role in boosting the show-up rate of leads, that will help you increase sales in the end. But adding too many characters (text) in the body, can actually backfire at your SMS wallet, and charging more than you expected.
Important Note
SMS reminders (text messages) come at additional price and the feature can be turned on by account admin only, in Event Builder.
By keeping your SMS wallet topped up in 
Settings → Billing menu you will ensure all text messages to be sent out.
iClosed provides text messages via 3rd party provider as part of the notification reminders that can be sent out internally and externally both. Setting up SMS reminders is available with 
AI Scheduler features:
Event Notifications in Event Setup (learn more here)
Automations → Workflows (learn more here)
General information
SMS text message format consists out of message segments (parts), where each segment contains usually up to 160 characters, but it all depends of the encoding the end carrier is using and type of characters you're using. SMS is not an email, where you can send unlimited number of characters without any costs.
Price cost of the SMS will be applied to message segments (parts), not per message written in the SMS Body.
Therefore, we strongly advise you to keep messages as short as possible, up to maximum two message segments (parts).
Pro tips
Number of characters for the Predefined template provided by iClosed in Notifications section is estimated to more than 160 characters (two message segments), which means, the cost of every SMS reminder sent out will be doubled.
Number of characters may vary, depending of the information pulled from Event variables (Merge fields) added to the text message body.
Whenever you start writing the SMS template you'll notice that iClosed calculates estimated number of characters even in combination with Variables added.
In the end, you'll see the number of the estimated SMS parts at the bottom.
How the message segment length is calculated
How the message segment length is calculated
Capacity
An SMS message can hold up to 140 bytes of information.
However, the actual number of characters you can use in a single segment depends on the types of characters in your message.
Character sets
If your message only uses characters from the GSM 03.38 character set (often referred to as the GSM 7-bit alphabet), you can have up to 150 characters in one message.
However, if your message contains characters not in this set, you're limited to 70 characters per message.
Automatic Encoding
When you send an SMS via iClosed, it will automatically choose the most efficient encoding for your message.
Long Text Messages
When your message exceeds the maximum character limit, it gets split into multiple segments (SMS parts).
Each segment includes extra information about the previous part. The recipient's device uses this information to display the message parts in the correct order.
Depending on the recipient's mobile service provider and device, these parts may appear as a single message or as separate ones.
This splitting reduces the character limit to 153 for GSM characters and 67 for non-GSM characters.
Estimating Message Parts
In case you'd like to know how many segments your SMS is going to be broken into into before sending it, check the bottom of the SMS template window, We'll estimate it for you.
Or you can use SMS length calculator tools available online (example https://thesmsworks.co.uk/sms-length-calculator)
Maximum Message Size
The largest size a message can be up to 1600 characters if it contains only GSM characters or 630 characters if it has non-GSM characters.
If your message exceeds these limits, it won't be sent out, and iClosed will return an "Invalid Message Exception."
Pro tips
Getting to know with all these tech stuff and understanding how SMS works will help you make the most out of your SMS reminders, at lowest cost possible.
But if you'd ask us to summarize it for you, this would be the answer:
Keep your text messages as short as possible, up to two segments max
In case you'd like to include company name in the text messages, but it's too long (e.g. Enterprise Premium Couching Group), add it as an acronym rather than including the whole name.
e.g. "Enterprise Premium Couching Group" has 33 characters, including spaces
Add EPCG instead (this goes for Event URL link as well)
Avoid emojis because they would pump up the character length
Combine email and SMS reminders, but use SMS reminder as the last one, hitting 15 to 45 minutes before the event start time
Use one SMS reminder for events available to be scheduled within 24 hours
Last but not least, keep your SMS reminders aligned with Event Time & Limits → Guest cannot schedule within setup
Combine Emails and SMS. It's proven as the best practice for sending the reminders out. Well organized timely touches sent to your leads will keep call attendance high.
Understanding SMS length
Understanding SMS length
Here're several examples of SMS messages to help you paint the picture better about how are message segments being counted and about character limits.
Example 1: Longer message with common characters
Message:
"Hello Carlos. Your Example Corp. bill of $100 is now available. Autopay is scheduled for next Thursday, April 9. To view the details of your bill, go to [link]."
Character count:
180
Summary:
Since this message uses regular characters from the GSM 03.38 alphabet, it has to be divided into two parts, with each part containing up to 153 GSM characters.
Cost:
It will be sent out as two message segments, meaning the cost of one SMS reminder will be doubled.
Example 2: Messages with Non-GSM Characters
Message:
"亚马逊公司是一家总部位于美国西雅图的跨国电子商务企业，业务起始于线上书店，不久之后商品走向多元化。杰夫·贝佐斯于1994年7月创建了这家公司。"
Character count:
71
Summary:
This message includes mostly non-GSM Chinese characters, which means it will be sent out as two segments, no matter if the character count is less than 160,
Due to encoding limitations, each part will be allowed to up to 67 characters.
Cost:
It will be sent out as two message segments, meaning the cost of one SMS reminder will be doubled.
Example 3: Handling Non-GSM Characters
Message:
"John: Your appointment with Dr. Salazar's office is scheduled for next Thursday at 4:30 pm. Reply YES to confirm, NO to reschedule."
Character count:
130
Summary:
This message contains a single non-GSM character, the closing single quote ('’), which differs from a regular apostrophe ('), often automatically replaced by word processors like Microsoft Word.
Due to the presence of this special character, the message is split into two message segments and in order to be sent out as one segment, you'd need to replace the closing single quote with a regular apostrophe before sending.
This case is super important for all customers who are copying SMS templates from other platforms or docs.
Cost:
1 message segment if adjustments in special characters are made.
If not, it will go out as two message segments, meaning cost will be doubled.
Additional information and how it looks on recipients end
Additional information and how it looks on recipients end
The phone number and message sending to the end recipient is adjusted according to the recipients country rules and regulations, and sometimes even according to the recipient provider if needed.
Message sending is being handled by provider, on a global iClosed app level, and it's not available to customize, and personalize sender information.
Recipients will not be able to respond back.
See below example of messages received on recipients phone:
SMS billing and costs
Overview
Overview
Navigate to 
Settings → Billing to buy SMS credits, track usage and remaining credits in the wallet.
In this menu you will be able to turn ON auto-recharge, which will ensure your SMS reminders are not being blocked.
Learn more about SMS wallet in Billing section here.
The text message prices vary between countries and regions, and in some cases even between carriers in the same country or region. These prices change regularly, and yes, usually increasing unfortunately.
We tend to update public documents regularly, to ensure you have accurate information available all the time.
Therefore, SMS costs differ depending of the number of text message segments, country/region, and carrier fees in countries and regions from where you're sending messages.
How to see invoice details for SMS charges?
How to see invoice details for SMS charges?
iClosed team is driven by desire to keep improving your favorite scheduler and unfortunately, downloading invoices for text message costs is something that we don't have available yet. But, it's something that is one of the top priorities on our Product improvement list, and you can expect to have this option live soon.
Until we have it released, please reach out to our Support team via chat button in the bottom right of your screen and we will send you screenshots of the SMS costs.
In case you have any questions about SMS, feel free to reach out to our knowledgeable Customer Support team via chat button, and we'll answer all of your questions in no time.
Learn more