# SMS and MMS limits and restrictions
The SMS protocol is subject to several limitations and restrictions. For example, there are technical limitations that limit the length of each SMS message and MMS has limitations on the size of the media file and length of the message body. There are also restrictions on the type of content that you can send using SMS and MMS. This topic discusses several of these limitations and restrictions.
When you're setting up SMS and MMS messaging in AWS End User Messaging SMS, you must consider these limitations and restrictions. As a best practice, you should also implement the techniques discussed in [SMS and MMS best practices](best-practices.md#best-practices-sms).
**Topics**
+ [SMS character limits](sms-limitations-character.md)
+ [MMS file types, size and character limits](mms-limitations-character.md)
+ [Message Parts per Second (MPS) limits](sms-limitations-mps.md)
+ [Message routes](#channels-sms-limitations-routes)
# SMS character limits
A single SMS message can contain up to 140 bytes of information. The number of characters you can include in a single SMS message depends on the type of characters the message contains.
If your message uses only characters in the GSM 03.38 character set, also known as the GSM 7-bit alphabet, it can contain up to 160 characters. If your message contains any characters that are outside of the GSM 03.38 character set, it can have up to 70 characters. When you send an SMS message, AWS End User Messaging SMS automatically determines the most efficient encoding to use.
When a message contains more than the maximum number of characters, the message is split into multiple parts. When messages are split into multiple parts, each part contains additional information about the message part that precedes it. When the recipient's device receives message parts that are separated in this way, it uses this additional information to confirm that all of the message parts are displayed in the correct order. Depending on the recipient's mobile carrier and device, multiple messages might be displayed as a single message, or as a sequence of separate messages. As a result, the number of characters in each message part is reduced to 153 for messages that only contain GSM 03.38 characters, or 67 for messages that contain other characters. You can estimate how many message parts your message contains before you send it by using SMS length calculator tools, several of which are available online. The maximum supported size of any message is 1530 GSM characters or 630 non-GSM characters. If the message size is greater than the supported size, the message will fail and AWS End User Messaging SMS will return an **Invalid Message Exception**. For more information about throughput and message size, see [What are the Message Parts per Second (MPS) limits](sms-limitations-mps.md).
AWS End User Messaging SMS does support all languages, however, depending on the recipient's mobile carrier and their regulations, certain symbols may be restricted on a case to case basis. When sending messages in languages that contain characters outside of the GSM 03.38 alphabet, the characters in each message part are reduced to 67.
**Important**
When you send a message that contains more than one message parts, you're charged for the number of message parts contained in the message. For more information about throughput and message size, see [What are the Message Parts per Second (MPS) limits](sms-limitations-mps.md).
## GSM 03.38 character set
The following table lists all of the characters that are present in the GSM 03.38 character set. If you send a message that includes only the characters shown in the following table, then the message can contain up to 160 characters.
| GSM 03.38 standard characters |
| --- |
| A | B | C | D | E | F | G | H | I | J | K | L | M |
| N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
| a | b | c | d | e | f | g | h | i | j | k | l | m |
| n | o | p | q | r | s | t | u | v | w | x | y | z |
| à | Å | å | Ä | ä | Ç | É | é | è | ì | Ñ | ñ | ò |
| Ø | ø | Ö | ö | ù | Ü | ü | Æ | æ | ß | 0 | 1 | 2 |
| 3 | 4 | 5 | 6 | 7 | 8 | 9 | & | \$1 | @ | : | , | ¤ |
| \$1 | = | \$1 | > | \$1 | - | ¡ | ¿ | ( | < | % | . | \$1 |
| £ | ? | " | ) | § | ; | ' | / | \$1 | ¥ | Δ | Φ | Γ |
| Λ | Ω | Π | Ψ | Σ | Θ | Ξ | | | | | | |
The GSM 03.38 character set includes several symbols in addition to those shown in the preceding table. However, each of these characters is counted as two characters because it also includes an invisible escape character:
+ ^
+ \$1
+ \$1
+ \$1
+ [
+ ]
+ \$1
+ \$1
+ €
Finally, the GSM 03.38 character set also includes the following nonprinted characters:
+ A space character.
+ A line feed control, which signifies the end of one line of text and the beginning of another.
+ A carriage return control, which moves to the beginning of a line of text (usually following a line feed character).
+ An escape control, which is automatically added to the characters in the preceding list.
## Example messages
This section contains several example SMS messages. For each example, this section shows the total number of characters, and the number of message parts for the message.
**Example 1: A long message that only contains characters in the GSM 03.38 alphabet**
The following message contains only characters that are in the GSM 03.38 alphabet.
`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 https://example.com/bill1.`
The preceding message contains 180 characters, so it has to be split into multiple message parts. When a message is split into multiple message parts, each part can contain 153 GSM 03.38 characters. As a result, this message is sent as two message parts.
**Example 2: A message that contains multi-byte characters**
The following message contains several Chinese characters, all of which are outside of the GSM 03.38 alphabet.
`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。`
The preceding message contains 71 characters. However, because almost all of the characters in the message are outside of the GSM 03.38 alphabet, it's sent as two message parts. Each of these message parts can contain a maximum of 67 characters.
**Example 3: A message that contains a single non-GSM character**
The following message contains a single character that isn't part of the GSM 03.38 alphabet. In this example, the character is a closing single quote (’), which is a different character from a regular apostrophe ('). Word processing applications, such as Microsoft Word, often automatically replace apostrophes with closing single quotes. If you draft your SMS messages in Microsoft Word and paste them into AWS End User Messaging SMS, remove these special characters and replace them with apostrophes.
`John: Your appointment with Dr. Salazar’s office is scheduled for next Thursday at 4:30pm. Reply YES to confirm, NO to reschedule.`
The preceding message contains 130 characters. However, because it contains the closing single quote character, which isn't part of the GSM 03.38 alphabet, it's sent as two message parts.
If you replace the closing single quote character in this message with an apostrophe, which is part of the GSM 03.38 alphabet, then the message is sent as a single message part.
# MMS file types, size and character limits
A single MMS media file can be up to 2 MB for all image types (gif, jpeg, png) and 600 KB in size for all audio and video media file types. The text message body of an MMS can contain 1600 from any character set. Unlike SMS, MMS message are not broken into multiple parts when they are sent. If you are sending large text message you may get better throughput sending an MMS message since they are not broken into multiple parts.
****
| File type | MIME types | Maximum file size |
| --- | --- | --- |
| Graphics Interchange Format | `image/gif` | 2 MB |
| Joint Photographic Experts Group | `image/jpeg` | 2 MB |
| Portable Network Graphics | `image/png` | 2 MB |
| Tag image file format | `image/tiff` | 600 KB |
| Third generation partnership project | `audio/3gpp`, `video/3gpp` | 600 KB |
| Third generation partnership project 2 | `audio/3gpp2`, `video/3gpp2` | 600 KB |
| Adaptive Multi-Rate | `audio/amr` | 600 KB |
| MPEG-4 | `audio/mp4`, `video/mp4` | 600 KB |
| Moving picture experts group | `audio/mpeg` Only MP3 files are supported for `audio/mpeg` | 600 KB |
| Ogg | `audio/ogg` | 600 KB |
| QuickTime | `video/quicktime` | 600 KB |
| WebM | `video/webm` | 600 KB |
| iCalendar | `text/calendar` | 600 KB |
| vCard | `text/vcard`, `text/x-vcard` | 600 KB |
| Portable Document Format | `application/pdf` | 600 KB |
# What are the Message Parts per Second (MPS) limits
SMS messages are delivered in 140-byte sections known as *message parts*. Messages that are very long, or that contain many multi-byte characters, are split into several message parts. These messages are usually re-assembled on the recipient's device, appearing as a single long message rather than several small ones. For more information about SMS character limits, see [SMS character limits](sms-limitations-character.md).
For this reason, SMS throughput limits, also referred to as throttling, are measured in *Message Parts per Second* (MPS)—that is, the maximum number of message parts that you can send in a second. Your MPS limit depends on the destination country of your messages, and the type of phone number, known as the *origination number*, that you use to send the message. For example, if you use a United States short code to send messages to recipients in the US, you can send 100 MPS. However, if you use a US toll-free number to send to US recipients, you are throttled to only send 3 MPS.
MMS message are delivered as a single *message part* and are not broken into multiple *message parts*. The maximum media file size can be up to 2MB for gif, jpeg, png, and 600KB in size for all other media file types and can contain up to 1600 characters, from any character set, in the message body, see [MMS file types, size and character limits](mms-limitations-character.md). If you are sending SMS messages that have more than 3 *message parts* you should consider sending an MMS message instead. For example if you send an SMS message with 481 GSM 03.38 characters then the SMS message will be split into 4 *message parts*. You are billed for each of those *message parts*. If you send the 481 GSM 03.38 characters in the MMS message body you are only billed for one *message parts*. Also only sending 1 MMS *message part* instead of 4 SMS *message parts* will increase your message throughput. For more information on pricing, see [AWS End User Messaging Pricing](https://aws.amazon.com//end-user-messaging/pricing/).
The following sections describe the MPS for various types of origination numbers and for various countries.
## Short codes
The following table shows general MPS limits for dedicated short codes.
| Geographic area | SMS MPS | MMS MPS |
| --- | --- | --- |
| United States (US) | 100 MPS | 40 MPS |
| Canada (CA) | 100 MPS | 40 MPS |
| All other countries and regions | Varies by country or region. | N/A |
## Long codes
The following table shows general MPS limits for dedicated long codes.
| Geographic area | SMS MPS | MMS MPS |
| --- | --- | --- |
| United States (US) (10DLC) | Default: 1 MPS per 10DLC number. Higher limits require a separate MPS increase request and are not automatically increased when you externally vet your company or after your campaign is approved. Final eligible rates are carrier-dependent based on brand score and campaign type. To submit a limit increase for your 10DLC numbers to match 10DLC campaign qualifications, see [Quotas for AWS End User Messaging SMS](quotas.md). | 1 MPS |
| Canada (CA) | 1 MPS | 1 MPS |
| All other countries and regions | 10 MPS | N/A |
## Toll-free numbers
Toll-free numbers are currently only available in the United States. US toll-free numbers support 3 MPS and require that you register the toll-free number. For more information about registering a toll-free number, see [US toll-free number registration form](registrations-tfn-register.md).
| Geographic area | SMS MPS | MMS MPS |
| --- | --- | --- |
| United States (US) | 3 MPS | 3 MPS |
**Important**
If your throughput requirements exceed 3 MPS, you should use a 10DLC number or a short code. If you purchase multiple toll-free numbers and attempt to distribute your throughput across them, the mobile carriers are likely to identify this as "snowshoeing" and filter all of your messages from their networks. For more information about "snowshoeing", see [Prohibited message content](best-practices.md#best-practices-sms-message-content)
## Sender IDs
The following table shows general MPS limits for sender IDs.
| Sender ID type | SMS MPS | MMS MPS |
| --- | --- | --- |
| Customer-defined using the AWS End User Messaging SMS API or from the AWS End User Messaging SMS console | 10 MPS | N/A |
## Shared routes
The following table shows general MPS limits for shared routes.
| Sender ID type | SMS MPS | MMS MPS |
| --- | --- | --- |
| Shared routes/customer-owned number | 20 MPS | N/A |
## Differences between message type and message routes
Messages sent through AWS End User Messaging SMS can either be promotional or transactional. A promotional message type is typically comprised of marketing or sales-related messages. Some countries or regions have quiet time hours when you're not permitted to send promotional messages. A transactional message type is for more time-sensitive messages, such as password resets or one-time passwords.
You pass the message type as an optional parameter using the [SendTextMessage](https://docs.aws.amazon.com//pinpoint/latest/apireference_smsvoicev2/API_SendTextMessage.html) operation of the AWS End User Messaging SMS and voice v2 API. In some cases you might use a sender ID as the originator, or you might have a shared pool of numbers. If you have both transactional and promotional numbers associated with your account for the destination country, AWS End User Messaging SMS chooses a transactional number by default. Delivery receipts and the Delivery dashboard show the route as either promotional or transactional, based on the chosen number.