Matty Erickson 
Keeping in touch with your customers keeps you in their thoughts and makes it more likely for them to do business with you, and that starts with making sure you have valid numbers. Phone number validation helps ensure the accuracy and security of user data, prevents fraud, and promotes effective communication: no more bounced messages.
This can improve the user experience for your customers by a huge margin, thus saving time, preventing fraud, and cutting costs. But how do you ensure that the phone numbers you collect are real, accurate, and reachable? Here are the best practices to keep in mind:
1. Check the Format
Manual processes done by humans will almost always have errors. People unintentionally leave extra spaces and random dashes or fail to select country codes entirely when inputting their phone numbers. You should use a basic format check to catch and mitigate these errors.
Additionally, ensuring that all phone numbers are formatted to the E.164 industry-standard format goes a long way in preventing these slip-ups.
2. Check for Line Type – Mobile, Landline and VoIP
The type of line determines how you will go ahead verifying the user and communicating with them. It will help you choose the right channel for your messaging and get the best conversion rates. Ideally, you want all users to provide mobile numbers since SMS and push notifications have the highest engagement and conversion rates, but that’s not always the case.
You can use a landline to send voice verification codes instead of the typical SMS. This is particularly useful if your business serves or is targeting an older age group that may not necessarily have a phone capable of receiving SMSs. On the other hand, a VoIP number may require you to add additional security measures – although it could be legitimate, it could also indicate fraudulent action.
Regardless of the line type your users have, you can leverage the reverse phone number lookup API by Trestle to get more contact information and ensure you can reach such customers at all times.
3. Build an Allow List of Country Codes
Unfortunately, some countries have a high incidence of fraud. Having a list of allowed countries when users are signing up helps you meet compliance requirements, reduce fraud, and manage registrations of new users smoothly. It simplifies the sign-up process for the user and your business.
4. Maintain a List of Carriers Based on Reputation
As is the case with the country code allow list, some carriers and prefixes have a high incidence of fraud and spam. Sorting phone numbers by the reputation of their carriers allows you to institute additional security measures to mitigate against fraudulent activities.
5. Check that Locations Match
Cross-reference the country code and other details of the phone number with the IP address from which the user is signing up.
Although a mismatch is not an automatic indicator of fraudulent activities, it gives you a chance to implement additional verification steps for invalid or high-risk phone numbers like premium or VoIP numbers – or if the carrier has a negative reputation.
Streamline Business Messaging Today
Keeping in touch with your customers or users is crucial to the success of your business, and that’s a process you should start by having the right phone numbers. Therefore, implementing best practices of phone number validation will help you a lot in this regard.
Trestle makes this journey easier by providing phone number validation, verification, and enrichment APIs so you don’t have to take on these tasks manually. Visit trestleiq.com today to find out more!
About Author
