# How do I prevent new user from using phone number already in use **URL:** \ **Category:** Ask for Help\ **Created:** [July 1, 2025, 12:51pm UTC](https://community.glideapps.com/t/how-do-i-prevent-new-user-from-using-phone-number-already-in-use/82859 "2025-07-01T12:51:38Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![oteb69](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/oteb69/32/83589_2.png) [@oteb69](https://community.glideapps.com/u/oteb69)\ **Post date:** [July 1, 2025, 12:51pm UTC](https://community.glideapps.com/t/how-do-i-prevent-new-user-from-using-phone-number-already-in-use/82859/1 "2025-07-01T12:51:38Z")
App is public with required sign-in. Sign up screen is submitted from a “set column values” action that includes default values needed by the app. How can I prevent a new user from using/inputting an already in use phone number. The submit button on an “set column values” action does not have “allow actions” conditions. ---
**Author:** ![Darren\_Murphy](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/darren_murphy/32/47326_2.png) [@Darren\_Murphy](https://community.glideapps.com/u/Darren_Murphy)\ **Post date:** [July 1, 2025, 12:54pm UTC](https://community.glideapps.com/t/how-do-i-prevent-new-user-from-using-phone-number-already-in-use/82859/2 "2025-07-01T12:54:25Z")
Are you using Row Owners in your User Profiles table? (assuming that the Phone number is stored in that table) ---
**Author:** ![oteb69](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/oteb69/32/83589_2.png) [@oteb69](https://community.glideapps.com/u/oteb69)\ **Post date:** [July 1, 2025, 1:16pm UTC](https://community.glideapps.com/t/how-do-i-prevent-new-user-from-using-phone-number-already-in-use/82859/3 "2025-07-01T13:16:19Z")
For the majority of columns yes..(including phone) ---
**Author:** ![oteb69](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/oteb69/32/83589_2.png) [@oteb69](https://community.glideapps.com/u/oteb69)\ **Post date:** [July 1, 2025, 1:20pm UTC](https://community.glideapps.com/t/how-do-i-prevent-new-user-from-using-phone-number-already-in-use/82859/4 "2025-07-01T13:20:02Z")
It still allows the new user to complete their profile, it just does not record the phone number in the user table. ---
**Author:** ![Darren\_Murphy](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/darren_murphy/32/47326_2.png) [@Darren\_Murphy](https://community.glideapps.com/u/Darren_Murphy)\ **Post date:** [July 1, 2025, 1:49pm UTC](https://community.glideapps.com/t/how-do-i-prevent-new-user-from-using-phone-number-already-in-use/82859/5 "2025-07-01T13:49:28Z")
> [@oteb69](#): > > For the majority of columns yes..(including phone) Not sure what you mean by that. When Row Owners are set, they apply to _all_ columns. The reason was asking is because if you are using Row Owners, then there is no easy way to check if a Phone Number is already in use. You would basically need to maintain a separate list of the numbers of all users somewhere that isn’t subject to Row Owners. And then of course you have the problem of matching numbers. Any given number can be written in many different ways. Take for example the US number: 212-456-7890. That could be written as: - 212-456-7890 - 2124567890 - 212-4567890 - +1 212-456-7890 - +1 2124567890 - etc… All valid variations of the same number. So it gets a bit tricky. ---
**Author:** ![ThinhDinh](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/thinhdinh/32/49_2.png) [@ThinhDinh](https://community.glideapps.com/u/ThinhDinh)\ **Post date:** [July 2, 2025, 12:11am UTC](https://community.glideapps.com/t/how-do-i-prevent-new-user-from-using-phone-number-already-in-use/82859/6 "2025-07-02T00:11:22Z")
> [@Darren\_Murphy](#): > > And then of course you have the problem of matching numbers. Any given number can be written in many different ways. Take for example the US number: 212-456-7890. That could be written as: In these cases, I would use [Numverify’s API](https://numverify.com/documentation) to get a standardized number (and also validate the number). They give you 100 free API calls per month.