KYC Nightmare. What Is SumSub and Why Users Say It Is Blocking Their Money on Crypto Platforms and Telegram (updated)

Not long ago, in December 2024, the monetization procedure on Telegram became more complicated. Users began to complain about issues with withdrawing funds. The reason is that a verification procedure was introduced for the Fragment platform, which is linked to the Telegram Wallet and the withdrawal of earnings from the messenger. Many claim that the process often fails for unclear reasons, and disputing verification rejections is nearly impossible.
And Telegram is just the tip of the iceberg. If verification fails on one service for some reason, problems begin on others, such as exchanges and online banks. The alleged culprit is the company SumSub. What kind of organization is this, and why is it considered the source of the problems — all in our material.
Know Your Customer
Let's start from afar. Dealing with money is a certain risk for any platform. To minimize it, companies must identify and establish the identity of the counterparty before carrying out a financial transaction.
If a service is used for fraud (money laundering, tax evasion, etc.), regulatory authorities will quickly step in. To prevent such cases, the Know Your Customer (KYC) practice was introduced in the industry.
In banks, crypto exchanges, and other platforms dealing with money, special KYC departments are created to verify clients. However, not all companies can (or want to) spend money on maintaining such departments. Therefore, they turn to third-party services — KYC operators.
Have you heard of SumSub?
SumSub is one of them. The company offers its clients a simple solution: a unified verification service for various platforms.
By eliminating fraud and verification hurdles, we aim to create a world where anyone—regardless of age, location, or computing skills—can securely access and use any service. To achieve this, we are developing a single, secure verification platform that is efficient, compliant, and free of country-specific barriers
They promise a "safe, accessible, and inclusive digital future for both users and businesses." Sounds attractive. But for many, SumSub's algorithms have become more of a problem than a blessing. What went wrong?
Wrong Turn
Web developer Dmitry Lukinin (name changed at the speaker's request) shared his negative experience with us. According to him, his Telegram Wallet verification was revoked at the beginning of last year. Initially, he didn't consider it a problem.
I forgot about this issue for about six months. Then I tried to pass verification on another site, uploaded all the documents, but they were rejected. It turned out that the verification I somehow failed in Telegram Wallet affected all my other verifications.
Dmitry tried to figure out what happened. The only link between Telegram Wallet and the service he tried to register on was the KYC operator SumSub.

I ended up on some SumSub blocklist. If some of your data gets there, you can't pass verifications in their system, and other services can also revoke your verification.
Thousands of platforms cooperate with SumSub. The list of clients on the official website includes various organizations — from gaming companies to exchanges and marketplaces.
The scariest scenario is when a person loses access to assets on a cryptocurrency exchange or some service due to a service like SumSub.
According to victims, these scenarios are becoming reality. People cannot withdraw money earned on Telegram channels, start auctions, or complete many other important tasks. Users don't realize that it is not the service itself rejecting their verification but a third-party contractor — SumSub. Those who manage to contact the real culprit barely receive support, which is often unhelpful.
SumSub takes a long time to respond and redirects users to the support of specific services. Meanwhile, service support relies on SumSub to save on KYC departments. The result is digital cancellation of the end user.
Why is this happening? To understand, we need another historical digression.
Too Big a Piece of the Pie?
SumSub is a relatively small project founded in 2015 by a group of Russian IT specialists. Three brothers from St. Petersburg teamed up with another like-minded person and launched a startup in London, offering KYC operator services.
By 2017, cryptocurrency exchanges were becoming increasingly popular and were happy to delegate user verification responsibilities to contractors.
The SumSub website states that between 2015 and 2017, their clients included BlaBlaCar, Toyota, Hyundai, and Avito. Today, the service has verified over a billion users — one-eighth of the planet's population — with a team of just over 450 people.
How do they manage it? The answer is neural networks. AI processes copies of personal documents and separates reliable users from bots and fraudsters.
Thanks to our in-house AI technology, we can verify users, businesses, and transactions all in one place—at any stage of the lifecycle.
Unfortunately, even robots can make mistakes, and no one seems in a hurry to correct them.
What's Next?
SumSub continues to attract new clients and expand its market presence. The company shares plans for 2025-2027 on its website.
The immediate plans include further tailoring onboarding solutions to specific market needs like the Middle East and APAC, and enhancing transaction monitoring and fraud prevention capabilities.
For those facing nearly insurmountable problems, this is alarming. Moreover, as Dmitry Lukinin noted, nothing prevents a malicious actor from exploiting the tool. If an ill-wisher or competitor tries to pass verification using your data and gets rejected, they could cut you off from your assets — potentially forever.
Technically, given the current progress in neural networks, it's possible to create a fake person, fake documents, upload them to some site. These fake documents fail verification. The system correlates these fake data with a real profile, and that profile gets a dark history and is sent to the blocklist.
Getting out of the blocklist, as we recall, is nearly impossible. On Trustpilot, SumSub's rating is declining. Users complain about the same issues as our speaker — only with different services like bybit, BingX, Nicehash, and many others.
Automation without a way to disable it when it doesn't work is clearly unacceptable for a system managing my finances! SumSub is stealing my money.
Negative reviews come from regular Trustpilot users, while positive ones are often from accounts with no other reviews. The conclusion is obvious.
Do you believe such praising reviews?
People left without platform access by SumSub agree — something needs to change.
I would personally like SumSub to change the appeal process. If a real person fails verification, there should be a mechanism to exit the blocklist.
Such a mechanism could involve video calls with support specialists or integration with local services that can confirm the client's identity.
***
Today, we observe a domino effect — the imperfection of one service causes problems on many other platforms. These are not just glitches but serious issues affecting people's financial interests. Depending on the legislation of each country, the situation may have legal consequences.
UPDATED 07.03.2025
We have been contacted by Sumsub representatives. The company provided a detailed response to the article. We are publishing it in full.
Sumsub is purely a technical service (software) provider operating on the SaaS basis; the client retains full control over the verification process. Sumsub does not make final decisions regarding user verification. Instead, first, Sumsub provides software to automate the onboarding process and compliance review, and may verify the authenticity of the submitted information from the user. Second, our clients decide on the approval or denial of any given user at their discretion. Third, Sumsub’s software is at all times used under a strict written instruction from our clients. That being said, a user approved by our system may be rejected by the client for their own reasons. Ultimately, the client determines whether to provide services to a particular user.
Sumsub does not support discrimination of users based on any criteria and does not intentionally reject users arbitrarily based on any factors whatsoever that are not dependent on the functionality selected and/or settings determined by our customer. Possible reasons to reject a user are if, for example:
There are reasonable doubts about the authenticity or validity of the provided information (e.g., suspectedly altered documents, documents not matching their official templates, a deepfake instead of a genuine “liveness” image, evidence of apparently forced verification, etc).
The data submitted by the user does not comply with the client’s internal policies and/or settings selected by the client for its Sumsub dashboard account, which must in turn align with all applicable legal requirements (e.g., a client lacking the license to operate in certain jurisdictions or providing a service not legally available for minors).
While we never disclose the nuances of any particular customer’s KYC procedures, multiple factors can influence any given user’s verification attempt, ranging from indications of forgery to more technical obstacles, such as mismatches between the user’s IP and declared place of residence or even the quality of lighting during the “liveness” check. It is entirely possible for the same issue to persist across multiple verification attempts, thereby causing rejection every time. Simultaneously, we confirm that our customers may instruct us to automatically decline those users that had previously been rejected on their projects, which they do in their sole discretion as part of their fraud prevention and other risk mitigation procedures. As we do not know the identity of the user mentioned in your material, we have no way of understanding the true reason behind their problem.
Unlike many other industry players, Sumsub offers applicant support to improve the verification experience. While final decisions as to whether a user should be onboarded rest with the respective client, we take user concerns seriously and, firstly, always aim to ensure each inquiry is timely redirected to the customer for whose services the user is applying and, secondly, upon request, assist the customer in re-evaluating the data provided by the user and correcting the verification result where it does not align with the customer’s settings.
While a system-related disruption affected some Fragment users in December 2024, it has since been resolved. Since Fragment supports a broad range of markets with varying verification requirements, some verification flow settings required adjustments after initial integration—a common occurrence for a new client.
For instance, AML procedures differ by region, and we worked closely with Fragment to fine-tune the system, ensuring a fair and non-discriminatory process. All affected users were invited to appeal and undergo re-verification and continue to have the option to request reconsideration via client support—an essential integration step.
-
Famous Doge Dog, Who Gave Us an Internet Meme and Cryptocurrency, Has Passed Away
-
How to delete a Telegram account?
-
Android Telegram Users at Risk: EvilLoader Vulnerability Still Unpatched
-
Hamster Kombat to Be Delisted from Crypto Exchanges
-
Hackers Attacked Bybit Crypto Exchange, Stealing Around $1.4 Billion