US and Canada Messaging

SMS messaging in the US is governed by the CTIA. Strict rules are in place to regulate US messaging, which makes the right SMS implementation a deceptively challenging experience. This guide outlines the best practices to ensure your messaging is in compliance with regulatory and industry standards.

Unlike SMS in other countries, SMS features and regulations in the US and Canada are directly dependent on the source number used for sending an SMS. In the US, there are three possible types of source numbers that one might use to send an SMS:

  1. Local phone numbers (a.k.a. long codes)
  2. Toll-free numbers (1-8xx)
  3. Short codes

To ensure high deliverability, it’s important to use the right source number type for your specific use case and daily volume. If you use the wrong source number, it may lead to excessive carrier filtering and poor delivery rates.

At Plivo, we support all the available source number types in the US. We work closely with our customers to help them choose the right product for their business.

Long codes

Long codes are regular 10-digit phone numbers capable of sending and receiving texts and voice calls.

Long codes have the following advantages over other source number types:

  • They are relatable,personal and therefore more likely to garner a response from the recipient.
  • They are easy to procure and set up. Plivo’s Phone Number API lets you programmatically search for and purchase phone numbers by region or prefix.

Long codes, however, are meant for person-to-person (P2P) communication, or conversational SMS. They do not perform well or high volume one-directional application-to-person (A2P) messaging use cases.

If your goal is to connect individuals on your platform without exposing their real phone numbers, then we recommend using a long code.

On the other hand, if you wish to send out notifications at high volumes, then long code is not the right number type for you.

To simplify working with long codes at scale, Plivo offers a dedicated product called Powerpack. With Powerpack, you can scale your conversational SMS use cases to millions of messages a day in seconds, all without having to write a single line of code!

Toll-free numbers

We’ve all come across toll-free numbers — the 1-8xx customer care phone numbers we’re accustomed to calling when we want to speak to a business representative.

Toll-free numbers are well-suited for business messaging since people already perceive toll-free numbers as business lines. They can be used to send text messages at up to 40 SMS messages per second at a relatively low cost.

You can acquire SMS-enabled toll-free numbers on the Plivo console or by using Plivo APIs and start reaching out to your customers. Beginning October 1, 2022, messaging from toll-free numbers is subject to the daily, weekly, and monthly limits.

  • US: If your messaging volume toward US destinations exceeds these limits, you need to verify your number.
  • Canada: All messages sent toward Canadian destinations must be sent from verified numbers.
Category Limit
Daily Limit 2,000 messages per day
Weekly Limit 12,000 messages per week
Monthly Limit  25,0000 messages per month

All messages, regardless of whether they were successfully delivered, count toward daily/weekly/monthly limits. If, for example, a customer attempts to send 25,000 messages on the first of the month, the first 2,000 messages will be sent and the remaining 23,000 will be blocked because of the daily limit. However, all 25,000 messages will count toward the weekly and monthly limits. Any attempt to send more messages the following day will fail with error code 960 because of the weekly limit.

Note that the day resets at 12:00 midnight PST, while the week resets Sunday at 12:00 midnight PST. Month refers specifically to a calendar month.

Verification is part of the Know Your Customer (KYC) initiatives undertaken by carriers in the North American market to increase trust and reduce spam from A2P messaging. Toll-free number verification serves the same purpose as registering long codes before they can be used as 10DLC numbers.

To initiate a verification request for a single Plivo toll-free number, fill out the Plivo Toll-Free Verification form. Plivo will submit the information you provide to the carriers, so please follow the instructions when filling out this form to avoid rejection by the carriers. If you need to submit verification requests for multiple numbers at once, please create a ticket for our support team.

Once you submit a request, Plivo passes it on to our carrier for review and moves the number to a “pending verification” stage. Numbers that are pending verification don’t have daily or weekly limits but do have a monthly limit of 200,000 messages per month. This provisional limit exists to allow customers to increase volume gradually. Additionally, messages sent from a number that’s pending verification are still subject to carrier scrutiny and filtering, so Plivo recommends that you switch your production traffic to a particular numbers only after it has been verified.

When the carrier notifies us of the successful completion of the verification request, we move the number to the “verified” stage, at which point it will be subject to the minimum amount of filtering.

If the verification request is rejected by the carrier, the number is moved to the “unverified” stage and the number will be subject to daily, weekly, and monthly limits again. We’ll send you an email that explains the reason for the rejection. Review the reason, consult with our support team, make changes, and resubmit your request.

Once verified, a number does not need to be re-verified for the same use case in the future. If you want to use the toll-free number for a different or an additional use case, you should submit a new verification request. Failure to do so can be considered noncompliance by the carriers and may result in your messaging services being suspended.

Short codes

Have you ever noticed that the text messages you receive from your bank or from other large institutions generally come from four- to seven-digit numbers that don’t look anything like regular phone numbers?

These numbers are called short codes: special SMS only source numbers, typically provisioned by enterprises for their business-critical communications. This is because short codes offer the best possible reliability at the highest possible scale (100 SMS per second).

The good news is that we’ve made short codes an affordable option for small and medium-sized businesses. Check out our short code pricing list.

Short codes have the following advantages over other source number products:

  • Very high deliverability at maximum throughput (up to 100 SMS per second). You can be sure of your delivery metrics thanks to handset delivery receipts that are generated when the text message is successfully received.
  • Highly predictable delivery rates since your use case and SMS content shall be preapproved even before you start.

The drawback is that the provisioning cycle for short codes is the longest out of all the available options — typically eight to twelve weeks. Why is that? Short codes and their corresponding use cases need to be preapproved by all network operators (Verizon, AT&T, T-Mobile, etc.) before you send one text out.

The good news is that once you’re preapproved, there will be no surprises once you actually go live.

A side-by-side comparison

Long Code Toll-Free Short Code
Regular phone numbers. Super personal. 1-8xx business phone numbers. Four- to seven-digit specially provisioned and preapproved source numbers.
Best for two-way conversational use cases. Best for business notifications and updates to customers. Best for business-critical notifications and updates to customers.
Ready to use. Buy using Plivo APIs or console. Provisioning toll-free numbers for SMS can take up to three business days. Provisioning short codes may take up to eight to twelve weeks.
Network delivery reports. Handset delivery reports. Handset delivery reports.
Spam filters are tuned to block high-volume texting, as long codes are meant for P2P communication. Super sensitive spam filters tuned to block unwanted bulk marketing campaigns. Relatively relaxed spam filters given that the use case and content must be preapproved to begin with.
Low rental cost. Relatively low rental cost for available throughput. Higher rental cost. Worth it for the high reliability at scale.