Practical use cases for detecting disposable phone numbers

Disposable numbers allow fraudsters to create fake accounts, bypass restrictions, and exploit platform incentives — often at scale.

In this article, we explore several practical use cases where disposable phone number detection can make a real difference, and how a solution like Rekonit can help product, fraud, and data teams.

Reduce costs associated with sending OTP text messages and promotional abuse

SMS verification is widely used during user sign-up, but every OTP message has a cost. For instance, OTP messaging services such as Twilio charge $0.0083 per text message sent. Each fake sign-up still triggers an OTP SMS, generating unnecessary costs.For high-volume products, this can represent thousands of wasted SMS messages every day.

Furthermore, promotional abuse can result in significant financial losses when the creation of fake accounts is poorly managed. In 2020, PayPal’s sign-up incentives backfired when fraudsters used bots to create 4.5 million fake accounts. This massive bot attack forced a major cleanup and wiped out nearly a quarter of the company’s market value.

How Rekonit helps

Rekonit can detect disposable numbers before sending the OTP. A typical flow becomes:

1. User enters phone number during registration in your app
2. Rekonit API checks the number
3. The API response tells you whether the phone number is disposable or not.
4. OTP is sent only to legitimate numbers

This simple step can significantly reduce SMS verification costs while also preventing fake accounts.

Cleaning CRM and Marketing Databases

Marketing teams often send SMS campaigns to users for promotions, re-engagement campaigns or transactional messages.

If part of the user base is made of disposable phone numbers, a portion of these messages will always be wasted. Disposable numbers in CRM systems can lead to:

• Higher messaging costs
• Lower campaign performance metrics
• Incorrect engagement analysis

How Rekonit helps

By detecting disposable numbers in the user base, companies can:

• Remove or flag suspicious numbers
• Exclude them from marketing campaigns and A/B tests
• Improve campaign targeting

This leads to cleaner CRM data and better marketing ROI.

Detecting Fake Accounts for Fraud Analysis

Fraud and risk teams need reliable signals to detect suspicious behavior, for example, to train a machine learning model to detect it. However, identifying fake users is often difficult because the ground truth is unclear. Many fraud detection systems rely on indirect signals like:

• IP address reputation
• Device fingerprints
• Behavioral anomalies

While useful, these signals do not always clearly indicate whether a user is fake.

How Rekonit helps

Disposable phone numbers can serve as a strong fraud signal. When a user signs up with a disposable number, there is a high probability that the account is not legitimate. This allows fraud teams to:

• Flag suspicious accounts earlier
• Investigate abuse patterns
• Build stronger fraud detection pipelines

Final Thoughts

Disposable phone numbers are widely used to bypass traditional phone verification systems. For many online platforms, they represent a hidden source of fraud, wasted costs, and distorted data. Detecting these numbers early can provide value across multiple teams:

• Product teams, by improving data quality
• Fraud teams, by identifying suspicious users
• Marketing teams, by cleaning CRM databases
• Engineering teams, by strengthening sign-up security

Solutions like Rekonit make it possible to detect disposable numbers in real time or at scale, helping companies maintain a healthier and more trustworthy user base.

Want to see how disposable number detection fits into your product? Get started with Rekonit and secure your sign-up flow in minutes.