Issue with missing SMS authentication codes
isolved is aware of continued reports from a small number of users who are not receiving SMS authentication codes.
UPDATE 5/14/2026: One of the issues has been resolved - but the matter is not closed. See update below.
We want to give you a clearer picture of what is going on with the SMS login code issue that was previously communicated as resolved.
The specific problem we identified at that time was fixed, and we have the data to back that up. However, some users are still occasionally not receiving their codes. These are separate issues and not related to the original problem.
Why This Is Happening Across the Industry
This is not unique to isolved. Starting in early 2025, major phone carriers in the U.S. changed how they handle business text messages. Instead of a one time approval process, carriers now actively monitor every business sending texts and can block or filter messages at any time if they see anything they do not like. A new federal rule that took effect in January 2026 added even more requirements on top of that. Every business sending SMS is dealing with this right now.
Why It Hits Platforms Like isolved Harder
Carriers treat big consumer brands like banks, Google, and Amazon differently. Those companies get top priority and special sending status. Platforms like isolved are in a trickier spot because we are sending on behalf of thousands of employer clients to millions of different users. Carriers look at that differently than they look at one big brand sending to its own customers. That means our messages are more likely to get caught in filters, even though all we are sending is a simple login code.
What We Have Done About It
- Added a block to stop users from requesting too many codes at once
- Reregistered our messaging campaigns to meet the latest carrier rules
- Changed our sending phone number
- Tested with a different SMS vendor to compare results
- Continuously monitoring our delivery data
Some situations are still outside our direct control, like a user accidentally marking our message as spam, their phone blocking it at the device level, or a carrier quietly tightening its filters. That said, we are actively working with our SMS vendors and pushing them for answers. We are not considering this issue closed.
It is also worth knowing that in some cases a code cannot be delivered because of something specific to that user phone number. This has nothing to do with carrier filtering. Common reasons include a landline number on file instead of a mobile number, a prepaid phone with no available balance, a number that was entered incorrectly, or a business phone line that is not set up for text messaging. In these situations the fix is simply correcting the phone number on file for that user.
How You Can Help
When you have an issue related to SMS login codes, please send PremierNow an email and include as much of the following as possible:
- What type of device the user is on (iPhone, Android, etc.)
- What carrier the user is on (AT&T, Verizon, T Mobile, etc.)
- Whether the user has ever received a code successfully before or if this is their first time
- How many times the user requested a code before reporting the issue
- Whether the code showed up in the user spam or junk text folder
- Whether other users at the same company are having the same issue or if it is isolated to one person
- The date and approximate time the issue occurred
The more detail you can provide, the faster we can pinpoint whether this is a carrier issue, a device issue, or something specific to that user.
We are also putting together guides to help you troubleshoot these situations. Those will be available soon.
Thank you for your patience.
We are pleased to confirm that the MFA SMS delivery delays previously reported have been resolved as of April 24th.
The root cause was a latency issue on the AT&T carrier path through our SMS provider. At its peak, a small percentage of AT&T messages experienced delivery delays of 30 seconds or more. Our provider worked with their aggregator and AT&T to correct the routing, and delivery times have since returned to normal across all carriers; virtually all messages are now arriving within expected timeframes.
We apologize for any disruption this caused and thank you for your patience while we worked through this with our vendor.
We received an update from our SMS provider about a fix applied Tuesday night (April 22) and we are seeing meaningful improvement in SMS MFA delivery times. Performance is now at its best level since this issue was identified, and T-Mobile and Verizon have returned to normal.
AT&T delivery times remain elevated compared to other carriers and the issue is not fully resolved. We are continuing to work with our provider and have asked them to keep us updated until AT&T performance is in line with the other carriers.
We will continue to keep you informed. We apologize for the inconvenience and thank you for your patience.
Our team has completed a 24-hour analysis of SMS delivery performance following recent aggregator changes. We are seeing meaningful improvement on AT&T traffic, with average latency and worst-case delivery times both trending down compared to the prior window. However, AT&T message delays have not fully resolved, and a recurring evening peak-hour pattern remains. T-Mobile and Verizon continue to perform within expected thresholds.
We are continuing to work closely with our vendors and AT&T to investigate the underlying throughput constraint and drive full resolution.
We will provide the next update as soon as we have new information or if the situation changes materially.
We apologize for the inconvenience and thank you for your continued patience.
We want to provide an update regarding the SMS delivery delays some of you may be experiencing. Our teams have confirmed that this issue is not caused by our platform directly; however, we are actively engaged with our vendor partners to investigate and resolve the situation.
This is a top priority for us, and we are applying all necessary resources to expedite a resolution. We understand the impact this may have on your operations and truly appreciate your patience and collaboration while we work through this.
Some users are continuing to experience issues receiving SMS authentication codes. While codes are being generated successfully on our end, we are aware that delivery is failing for a number of users. We are treating this issue with the utmost urgency. We have held several meetings with our SMS delivery provider and are actively working toward a resolution. In parallel, we are also in the process of evaluating an alternate vendor to ensure delivery reliability going forward. We will continue to provide updates as soon as there is progress to share.
In the meantime, we recommend the following: If an alternative login method is available (email verification, passkey, or authenticator app), please use that as a temporary workaround. Thank you for your continued patience as we work to resolve this as quickly as possible.
Recommended Workarounds
Best Practice Solution
Use an alternative login method such as Passkey or Authenticator App.
Passkeys provide a more secure and reliable login experience and are not impacted by SMS delivery or carrier-level filtering.
You and your employees can use these guides to help you get them set up:
How to Set up a Passkey for isolved
How to Set up an Authenticator App for isolved
Alternative Workaround
Follow these steps to improve delivery if you are still relying on SMS.
- Confirm that the user's mobile number on file is correct.
- Check the MFA Security level on your account.
Use this guide and reach out to PremierNow support if you have questions on whether the level of security you require for your employees should be changed.
- Have the user save the isolved SMS numbers as contacts in their phone to prevent messages from being filtered as spam.
The phone numbers are +1-256-826-0180 and +1-740-298-9104.
- Have the user check their junk/spam and filtering/screening settings.
Users should check Spam or Junk message folders, or temporarily disable SMS spam or message-blocking settings (especially on iOS). Check screened messages by performing the following steps:
On iPhone (iOS)
- Open the Messages app.
- Tap on Filters (usually at the top left) or scroll down to see folders.
- Select Unknown Senders to see messages from numbers not in your contacts.
On Android (Google Messages)
- Open Google Messages.
- Tap the three dots (More options) or your profile picture, then go to Settings > Spam & blocked or Spam protection to find filtered messages.
On Android (Samsung Messages/Other Apps)
Look for folders like “Spam,” “Filtered,” or “Blocked” directly in the app’s main menu. Some apps might show a “Show filtered SMS” link on the home screen.