SMS country specific marketing compliance – Ometria Help Centre

If you're interested in sending SMS campaigns please get in touch with your Customer Success Representative.

Each country has its own guidelines for sending marketing communications via SMS.

Use this page as a guide and consult your Customer Success Representative if you're unsure.

Warning: This is not legal advice. You are required to work with qualified legal counsel to understand applicable laws in your markets.

General best practices

We recommend that you follow these guidelines in all locales:

Get opt-in consent from your contacts before sending marketing communications to them.
Only send SMS during your contacts' daytime hours. See: SMS quiet hours
Support STOP messages in your contact's local language.


Locale	Canada
ISO code	CAN
Region	North America
Mobile country code	310, 311
Dialling code	+1
Double opt-in	It is illegal to send marketing SMS messages without obtaining the necessary consent. The recipient must have explicitly agreed to receive such messages. Double opt-in is considered a best practice. See: Canada's anti-spam legislation (CASL)
Preferred sender IDs	Long code: 10DLC Long code: Toll free Two-way SMS - Virtual number, i.e. longcodes See: Sender IDs for SMS
Quiet hours	21:00 - 08:00 (9pm - 8am) See also: SMS quiet hours


Locale	United Kingdom
ISO code	GB
Region	Europe
Mobile country code	234, 235
Dialling code	+44
Double opt-in	Not required.
Preferred sender IDs	Transactional SMS - Alphanumeric codes Marketing SMS - Alphanumeric codes Two-way SMS - Virtual number, i.e. longcodes See: Sender IDs for SMS
Quiet hours	20:00 - 09:00 (8pm - 9am) See also: SMS quiet hours

All promotional traffic must include an opt-out method. See: Managing SMS marketing preferences
Generic URL shortening (i.e. the link no longer contains your domain) is not allowed. Ometria automatically shortens your links for you - please don't use an external link shortening service.
Sending cannabis related content is strictly prohibited, though you can send CBD related content.
All international (non-UK) numbers and shortcodes will be blocked.

In 2023, BT introduced regulations to reduce fraudulent messaging and smishing (SMS phishing) attempts.

Messages sent to BT subscribers with alphanumeric sender IDs related to specific brands will be blocked by default.


Locale	United States
ISO code	US
Region	North America
Mobile country code	310, 311
Dialling code	+1
Double opt-in	It is illegal to send marketing SMS messages without obtaining the necessary consent. Consent must be clear and specific, indicating that the recipient agrees to receive marketing messages from the sender. Double opt-in is considered a best practice as it gives the clearest indication of consent. Violating the TCPA can result in substantial penalties, including fines from $500 to $1,500 per unsolicited message. Class action lawsuits can also arise from TCPA violations, potentially leading to significant financial liability. See: Telephone Consumer Protection Act
Preferred sender IDs	Long code: 10DLC Long code: Toll free Two-way SMS - Virtual number, i.e. longcodes See: Sender IDs for SMS
Quiet hours	The Telephone Consumer Protection Act prohibits sending text messages anytime before 9am and after 8pm in the recipient's time zone, but some states have more restrictive rules, e.g. Florida - between 8pm and 8am. See also: SMS quiet hours

In the following states, marketers are restricted to sending a maximum of three SMS per 24 hours:

In Mississippi you can't send marketing SMS on Sundays.

See also: Frequency capping