This page lists all known limitations for the SMS and Call services. Please be guided accordingly.
In CINNOX, a single (1) SMS is limited to 160 chars for English text, while 70 chars for non-English text (universal code) like Chinese and Japanese scripts.
If the SMS text exceeds the single SMS limit, it splits into smaller messages for transmission.

Some countries do not allow sending an SMS with URL content (e.g. Mainland China (+86) & Taiwan (+886)). The SMS can be sent out but may not be delivered.

Please ensure that your phone number recipient is a mobile number. A non-mobile number may not be able to receive SMS messages. A warning is displayed in the dialogue window when a phone number is non-mobile or invalid.

According to the regulations and requirements of the China carrier, you must register a template with the carrier to send an SMS to a mainland China number (+86). The registered template will only be delivered if the SMS content matches exactly. Suppose you still send SMS with the content without a registered template, or the actual content does not match 100% with the registered template (e.g. a variable field containing an index filled with a string). In that case, it will be sent out but void and incur a cost.Please contact your account manager to learn more about the procedure and requirements for registering a carrier template.
All message templates must be authorised and registered through CINNOX, so customers must prepare the "Letter of Authorisation" for the template application. Please get in touch with your account manager for more details about the "Letter of Authorisation".
Users are responsible for the authenticity, accuracy and legitimacy of sent information. SMS is filtered out sensitive information with a violation of law and regulations; the information may not contain SMS message content with any one of the following:
Due to telecom regulations varying from place to place, Service Numbers set as a Caller ID (CLI) or SMS Sender ID are not guaranteed to be displayed to recipients.

Caller ID
CINNOX International Direct Dial (IDD) calls to some regions and countries display country codes even when calling to the same region and country. This rule depends on the regions' and countries' telecommunications policies.

In-Call Advertisement Video:
Video Call Functionality:
Voice Functionality (Voice, Video, Conferencing, Screen Sharing, Voice Message Recording):
The following countries have some call restrictions depending on their local telecommunications policies.
| Country | Limitation |
|---|---|
| Australia | Calling in Australia with the following categories will be blocked by Australian Carriers. * No CLI * Invalid CLI (A-number which does not conform to international standards (ITU-T Recommendation E164), or is an invalid number length, or is a dummy CLI) * Calls with an Australian A-number (+61), except for international roaming numbers. Calls with +61 A-numbers can only be legitimately sent on Australian domestic switches. * alls with an Australian domestic Free call or other inbound calling numbers as CLI * Calls with a CLI that is known to be a source of scam calls |
| Fiji | The Fiji Toll-Free number can only be connected with callers using a landline number. It is not supported for callers using a mobile phone. |
| France | Calling numbers from the international with a CLI or Protocol Addressing Information (PAI) or Personally Identifiable Information (PPI) or RPI or Calling Party Number or Generic Number) starting with +33 1/+33 2/ +33 3/ +33 4/ +33 5 and +33 9 and toward a called number starting with + 33 (excepted MSRN ranges +33 653/ +33 654/+33 655 will be systematically filtered. |
| Hong Kong | Calling Hong Kong IDD using Hong Kong fixed line number CLI is not allowed. Hong Kong mobile numbers beginning with 8524, 8525, 8526, 8529, and part of 8527 and 8528 CLI are allowed. Calling Hong Kong DID from overseas will replace the CLI with ANONYMOUS or a particular Hong Kong number. |
| India | Calling a number +91, using a fixed line +91, is restricted per the India Department of Telecommunication (DOT) Guidelines. |
| Indonesia | Calling a fixed line number +62 using fixed line +62 is not allowed. * International Direct Dialling (IDD) using 001, 008, 007, etc * 001 803 is International Toll-Free (ITF), and 0800 is Domestic Toll-Free. * IDD services must be activated to dial even local callers for international toll-free numbers. |
| Japan | The CLI +81 for domestic mobile networks will be removed during international calls. For a landline, it depends on the carrier to which the call terminates. Most carriers block the CLI when it is an international call starting with +81. This is the policy to prevent fraud calls. |
| Mainland China | Calling in Mainland China is not allowed for the following: * China termination calls * Without caller number * Invalid caller number * Caller number with NOA=national * Caller number with number incomplete (NI=1) * Caller number with presentation restricted (PI=1) * Caller number starts with 86(1-9)fixed number (86 calling 86) * False roaming caller starts with 861 mobile number * A number frequently calling in a short time. * A caller number is your own number, aka Bring Your Own Number (BYON) Calling in Mainland China is considered abnormal and may be blocked by the China local operators for the following: * 4001 China toll-free cannot be used as a Calling Line Identity (CLI) * The caller number is too short or longer than 13 digits * The caller number starts with 0, e.g. 08601321346 * Low Answer Seizure Ratio (ASR) means no unsolicited calls - too many call attempts vs the number of calls getting picked up. * Low Average Call Duration (ACD) means the average call duration is too short (e.g. all calls are below 1 minute). The typical call duration should be at least 2-3 minutes * Spam (junk) calls |
| Malaysia | Calling a number +60, using +60, the traffic is considered a spam call, and it will be blocked by operators. This is also a government regulation to protect their people from fraudulent calls. |
| Philippines | Calling a fixed line number +63, using a fixed line +63, is not allowed. |
| Taiwan | Calling the Taiwan Toll-Free number is not guaranteed for callers outside Taiwan. Criteria must be met to connect the call: * Automatic Number Identification (ANI) must be Taiwan's number * Type of Number (TON) must set National * Numbering Plan Identifier (NPI) set as Integrated Services Digital Network (ISDN) * No call status on layer3 * Calling the Taiwan IDD using the Taiwan fixed number CLI beginning with 8860 up to 8868 is not allowed. * You can only make calls to Taiwan numbers via CINNOX using a local termination number. Contact us to obtain a local termination number. |
| Thailand | In-country call (Calling a number 66, using 66) is not allowed. This issue is due to the policy of the Thailand National Broadcasting and Telecommunications Commission (NBTC) to block spam calls. * It blocks incoming calls from international carriers when the calling number is with "Thailand's fixed line number, such as 660, 661, 662, 663, 664, 665, 667, 02, 03, 04, 05, 06, 07". * It allows incoming calls from international carriers when the number is "Thailand Mobile Station Roaming Number (MSRN)". Using Thailand mobile number "+66 8" CLI will be replaced with "+698", e.g., +66 82134567 will become +698 82134567 |
| Vietnam | According to local regulations, calling a Vietnam number with international routes is not allowed. |
While many of our customers successfully receive SMS OTPs from various platforms and services, we cannot guarantee this for all providers. The ability to deliver verification SMS depends on each third-party provider’s policies, which are outside our control.