Help Articles

By Narayana Sami April 11, 2025
A2P 10DLC - Stay Compliant Approved for A2P 10DLC - What's Next? Once your A2P 10DLC application has been approved, carriers will continue to monitor your SMS traffic. If you fail to follow guidelines, especially in those first messages, carriers will randomly filter other messages across your account (not necessarily the first lead that had the violation) until you fully comply. Repeat offenders may have their SMS capabilities in Close suspended, and non-compliance fees may apply. Read further for details A2P 10DLC GUIDELINES ​ To avoid SMS filtering and repercussions to your SMS capabilities in Close, strictly follow the guidelines below: 1. Consent and opt-in Ensure that you only send messages to mobile users who have provided consent (opted-in) to receive messages from you. If at any point SMS capabilities are suspended in your account, Twilio will require you to provide proof of consent for some random numbers. If you are getting consent through phone calls, then have the lead send the first message using a keyword like "START." This message will act as proof of consent. 2 . Sender identification ​Every message you send must clearly identify you (the party that obtained the opt-in from the recipient) as the sender, except in follow-up messages of an ongoing conversation. That is, the first message should have an introduction of who you are and why you are contacting the end user. Example: "Hey Brian, this is Carol from Close.com....." ​ 3. Opt-out language ​The initial message that you send to an individual needs to include the following language: "Reply STOP to unsubscribe," or the equivalent using another standard opt-out keyword, such as STOPALL, UNSUBSCRIBE, CANCEL, END, and QUIT. If you are contacting the same recipients multiple times per month, you do not need to provide opt-out instructions in every message, but you must do it at least once per month. If you are sending messages to users repeatedly over a long period of time, you should check in with your recipients at least once every 18 months to ensure they still want to receive messages from you. The mobile number you are sending messages to may have changed owners, or the recipient may not remember giving consent to receive messages from you. Example: "Hey Brian, this is Carol from Close.com reminding you of our call at 3pm. If you no longer wish to receive SMS notifications, reply STOP" ​4. High-key messaging metrics Carriers will continuously monitor for two metrics: a)​​ Opt-out rate High opt-out rates indicate that you must be sending unsolicited messages to people who didn't explicitly opt in to receive messages from you. Such people are more likely to object and generate complaints, which will lead to your account being flagged for noncompliancy. Countinously monitor your opt out rate and review your lead generation methods if the rates are too high. ​ ​b) High delivery error rate This covers errors: 30003 - Unreachable destination handset 30005 - Unknown destination handset 30006 - Landline or unreachable carrier Multiple failed deliveries indicate: You may be attempting to contact numbers that are no longer in service, or are unreachable, such as landlines and/or external carrier filters, are refusing to deliver your messages. Same or similar message sent across a large number of phone numbers -carriers do not permit bulk sending identical messages across many phone numbers in a short time frame without prior business justification. c) Number of incoming messages When the ratio of incoming to outgoing SMS on a Long Number is more than 1:3 (Outgoing SMS -> Incoming SMS), it signals to carriers that your recepients aren't engaged thus they may not have opted into your messages. 5. Message contents a) URL shortening: Do not send links that have been shortened using shared public URL shorteners, such as TinyUrl or free Bitly links. United States carrier policies discourage the use of shared public URL shorteners, and state that your URL shortener should be both proprietary and properly branded ( details here ). b) Don’t use emojis, lots of exclamation marks or unnecessary special characters/capitalization, and watch your grammar and spelling. Typically, these messages are structured in a way to attempt to evade detection of unwanted messaging, and your messages will be filtered. c) Do not send content that is illegal in your sending area, or is forbidden by carriers. See Forbidden message categories for SMS and MMS in the US and Canada for additional information. 6. SMS Character Limit A single SMS message technically supports up to 160 characters, or up to 70 if the message contains one or more Unicode characters (such as emoji or Chinese characters). However, modern phones and mobile networks support message concatenation, which enables longer messages to be sent. Messages longer than 160 characters are automatically split into parts (called "segments") and then re-assembled when they are received. Message concatenation allows you to send long SMS messages, but this increases your per-message cost, because SMS are billed per segment. See more here . When your messages per second increases, you are likely to appear like you are bulk messaging which will lead to filtering. Workflows Ensure your messages, especially templates used in Workflows, stay below the 160 character limits. Why do message filtering systems exist? Message filtering systems exist for two reasons: 1. Protecting mobile subscribers from unwanted messaging such as spam, fraud, or abuse Unwanted messaging is a huge issue in the messaging industry; unwanted messages can result in complaints, fines, or outright disconnection by carriers. Mobile users who receive lots of spam or other unwanted messages may decide to start opting out of or ignoring all messages from businesses, even legitimate ones who follow all rules and best practices. For these reasons, it is in everyone’s interest – Twilio(our telephony partner), wireless carriers, regulators, and most importantly our customers – to ensure that unwanted messaging is not allowed over Twilio’s carrier connections. 2. Enforcing rules or regulations about what types of messaging are allowed to that country or mobile network Depending on the country, laws or regulations may put restrictions on certain types of messaging, or even forbid certain things altogether. Messages which violate these rules may be subject to filtering. These rules and regulations may also change over time. In the U.S. and Canada, application-to-person (A2P) type messaging was historically not allowed to be sent using local 10-digit long code phone numbers. In 2021, however, Twilio and U.S. carriers are launching the A2P 10DLC(coming soon to Close as well) solution which permits A2P messaging via long code to United States recipients. How do spam filters work? Spam filters vary heavily from carrier to carrier, and can be changed overnight without warning. If you are hosting a number in Close, SMS is taken care of by our provider, Twilio. SMS can be marked as spam by Twilio's carriers or the receiving leg’s carrier. Algorithms and systems will be scanning SMS for certain keywords, SMS length and other criteria that may come across as ‘spammy’ in nature and block them before they are delivered. Message filtering can range from a simple static list of prohibited terms, to advanced machine learning systems that constantly adapt based on the messages passing through them One SMS that you sent to a customer may be delivered as expected today and the exact same message to another customer may be flagged as spam tomorrow. Close has no control over these filters and they are incredibly volatile. So keep reading for some more insight! How do I know if my messages are being filtered? You will notice an error on the SMS activity in Close. If you hover your cursor over the error message, you will see the reason why it was undelivered.Filtred messages will fail with Error 30007 "Message Delivery - Carrier Violation": The destination carrier is filtering out your messages for delivery. The content of your message was flagged as going against carrier guidelines. If you are avoiding all of the above and notice your number is still being flagged as spam, reach out to support@close.com for next steps. Close does not control spam filters but we can loop in our telephony provider to give a more concrete reason why the SMS was blocked and point you in the right direction. A2P 10DLC Non-Compliance Fees T-Mobile has instituted fees for non-compliant A2P SMS traffic that results in a Severity-0 violation. What is a Severity-0 violation? A Sev-0, (Severity-0) represents the most harmful violation to consumers and is the highest level of escalation and applies across all products (SMS or MMS, Short Code, Toll-Free, and 10DLC) that transverse T-Mobile’s network. If you send messages to T-Mobile’s network that fall into this category, you’ll be fined a non-compliance fee The fees depend on the category of the violation - see the fines and tiers below. Tier 1: $2,000 For phishing attempts, smishing, and social engineering. Social Engineering refers to the practice of targeting individuals in a way that manipulates individuals to reveal private information like credit card numbers, or social security numbers. Tier 2: $1,000 For illegal content (must be illegal in all 50 states and federally.) Illegal content includes, but is not limited to, Cannabis, Marijuana, CBD, Illegal, Prescriptions and Solicitation. Tier 3: $500 ​For all other violations including, but not limited to, S.H.A.F.T. S.H.A.F.T.= Sex, Hate, Alcohol, Firearms, Tobacco (including cannabis).
By Narayana Sami April 11, 2025
A2P 10DLC A2P 10DLC is a new messaging standard introduced by major US carriers that requires all companies sending A2P(Application to person) SMS traffic to be registered. This is the case regardless of whether you are sending a bulk sales campaign or you just use SMS for occasional transactional messages. This only applies to companies messaging in the US and US territories using 10-digit long code phone numbers (like your Close phone numbers). It allows businesses to send Application-to-Person (A2P) type messages. Carriers in the US consider all Close traffic to be A2P. Registering your business provides better delivery quality and lower filtering <> currently imposed by carriers on unregistered traffic. Why are carriers enforcing registration? Protecting mobile subscribers from unsolicited messaging such as spam, fraud, or abuse is the main reason registration is mandatory. Unwanted messaging is a huge issue in the messaging industry; unwanted messages can result in complaints, fines, or outright disconnection by carriers. Mobile users who receive a lot of spam or other unwanted messages may decide to start opting out of or ignoring all messages from businesses, even legitimate ones who follow all rules and best practices. US carriers (ATT/TMO/VZW - TMO being the most strict) are making it more difficult to send A2P-type SMS due to high rates of SMS fraud in the US, which is why such a vigorous process is in place. Registration Fees Campaign registration carries the following one-time fees (a brand and a campaign is registered together): $5 for Low-Volume Standard Brands (organizations sending less than 6000 messages a day) $52 for Standard Brands (organizations sending more than 6000 messages a day). $5 - Sole Proprietor Brands without EIN $18 - One time Campaign verification fee for all of the 3 above. A Campaign registration has a $2 ($2.5 for Sole Proprietor Brands without EIN, $12 for organizations that send more than 6000 message segments per month) recurring monthly fee after being approved. This is passed down from our telephony partner Twilio. What information will you require from me to be registered? 1. Your business registration details including: Business legal name Business address Business type (Sole Proprietorship, Partnership, Corporation, Co-operative, Limited Liability Corporation, Non-profit Corporation) Business industry Business registration number and registration type (ex: EIN Tax ID) Business regions of operations (what countries and/or continents) Website URL Contact data for an authorized company representatives 2. SMS Traffic Use-case and Opt-in Processes This includes how much SMS traffic you anticipate having, along with how your customers consent to receiving SMS messages from you. An opt-in process is required. Ensure Campaign Approval After you have submitted your information, we will submit it to our telephony partner Twilio for approval. Your registration is approved by a 3rd party board namely Campaign Registry . For your data to be approved, certain things have to be in order - see best practices here . Campaigns can be rejected. If this happens, you will need to resubmit your information and you will be charged another fee for each resubmission. To ensure your campaigns are approved the first submission, you will need to: 1. Ensure data accuracy and consistency. Double-check that your company details are accurate. See below common mistakes that lead to campaign rejections. 2. Campaign Use-case . Be as descriptive as possible to describe how you use SMS in Close. For example: We are a real estate company so we use this to communicate with buyers and sellers who have opted in to our network of agents so that we can share with each other properties in the market to coordinate viewings, request for new listings and close on sold properties. 3. Ensure your use case involves consumer consent before sending messages . A clear opt-in process is mandatory even if you only send trasactional messages. You must show that your SMS recipients are consenting to receive SMS from you. Creating an opt-in process Before sending SMS in Close, you must first obtain consent from your leads. Please note that an opt-in process is mandatory and nonnegotiable. Sending unsolicited SMS may put your account at risk of being suspended . If you don't have an opt-in process, create one before starting your registration process. Acceptable opt-in processes Your campaign registration will be rejected without a proper opt-in process. The below guidelines give you the necessary language to make sure registration is approved without a lot of back and forth. Your opt-in process may vary depending on your lead generation methods. You can go with either of the below: 1. Sign-up through webforms If your leads come through sign-ups or filling webforms/surveys, you must include a way for them to know that providing a phone number means they will be receiving SMS from your brand. Examples: End users opt-in by visiting https://example.com/signup/ and adding their phone numbers. They then check a box agreeing to receive text messages from Close.com. 2. Booking Links Booking softwares such as Calendly and Savvycal that give the option to collect lead data when booking a meeting will be proof of opt-in. They must include a checkbox where a lead can explicitly consent to receiving SMS. For example: Users share their phone numbers when booking a meeting on our Savvycal booking link https://savvycal.com/bookcall. They check a checkbox to consent to receive SMS from Close.com. The consent message must include: Program name and/or a description of the messages that will be sent. Organization or individual being represented in the initial message. Fee disclosure ("Message and data rates may apply"). Service delivery frequency or recurring messages disclosure ("4 messages per month", "Message frequency varies", "1 message per login", etc). Customer care information (typically "Text HELP for help" or Help at XXX-XXX-XXXX). Opt out instructions (typically "Text STOP to unsubscribe"). Link to Privacy Policy describing how end user opt-in information will be used. Link to Terms and Conditions describing Terms of Service. Incorporate a checkbox option that end-users must select in order to receive SMS messaging. The checkbox cannot be pre-selected. The checkbox provides the end-user the ability to agree, or not agree, to receive SMS messaging. Example of a good consent message: By submitting this form, you agree to receive transaction messages from {{YOUR COMPANY NAME}}. Text and data rates may apply. Message frequency varies. Reply STOP to unsubscribe or HELP for help. To view our privacy policy, go to {{LINK TO YOUR PRIVACY POLICY}}.*** 3. Text If you don't have a sign up form where customers sign up to your services, then your leads will need to initiate the first message by sending the keyword "START" to your Close phone numbers. If we use this method, your first message before starting a normal conversation must be something like: "{{COMPANY NAME}}: Thank you for choosing us. We will use SMS to schedule your next appointment. You can reply STOP at anytime to opt out." What happens after registration? After a successful registration and your campaign use case has been approved you will be assigned a trust score . This is your company's credibility according to carriers. This will determine how many SMS messages you are allowed to send per day, per carrier. If you exceed this threshold, your messages will fail to be sent. To keep your trust score high, please make sure you abide by: Opt-in . Only send SMS to customers who have opted in to receive SMS from you. This will make sure that your opt-out rate remains low. A high opt-out rate will indicate to carriers that you are sending cold SMS, which is illegal. If you are using SMS for cold outreach, make sure to receive consent via email or call first. If your account is ever flagged for high opt-out rates, you will be at risk of having it suspended if you don't provide proof of opt-in for a random set of contacted leads picked by the affected carrier. High Failure Rate. Use third-party sites to validate your contact list before you import them to Close and start sending SMS. That way, you are not sending SMS to landlines, which is another signal to carriers of spam messages without consent. A high error rate due to invalid numbers or landlines will significantly lower your trust score. New Numbers If your account is already approved for A2P 10DLC, any new numbers you buy will be automatically added to your approved campaign. Keep in mind that the number needs to be registered with carriers as well. This process can take up to 8-10 days, as the change has to propagate across several stakeholders/carriers. OPT-OUT Twilio, our telephony partner handles opt-out automatically if a lead responds to your messages with any of STOP, STOPALL, UNSUBSCRIBE, CANCEL, END, or QUIT, Any of these STOP keyword replies will prevent a customer from receiving new messages from the specific Close phone number they're responding to. When Twilio receives one of these replies, they will create a "block list" entry on their side. Once they have a block list entry for a particular recipient phone number, any future attempts to message them will fail with Error Code 21610 - Message cannot be sent to the 'To' number because the customer has replied with STOP. Recipients can disable this and resume receiving messages with the START, YES, or UNSTOP commands as outlined below. Only single-word messages will trigger the block. So, for example, replying STOP will stop the customer from receiving messages from that particular Close number, but replying "STOP PLEASE" or "PLEASE CANCEL" will not. Please note that these STOP keyword replies only apply to the most recent number that messaged the recipient. If you are using more than one Toll-Free number or Long Code for sending messages, you must take additional action separate from Twilio to prevent these customers from receiving messages from your other numbers. We recommend deleting the contact's numbers on your side when one of these message responses is received. For more info, see full Twilio Messaging Policy and Acceptable Use Policy (AUP) . See how to stay compliant after approval here <>.