Prevent Users From Abusing Trials

Post author
Doc Waller

So, I'm noticing at least one user creating multiple GMAIL accounts, with only small changes/tweaks in the name, so they can sign-up for our Free Trials multiple times without paying. 

I'm wondering if there's any way Memberstack can help in preventing or identifying this automatically. I know it helps with "throw-away" emails, but I'm not sure if it helps with people generating multiple real GMAIL accounts. 

Let me know if anyone else has experienced this. How did you go about it? Did you manually delete that users account after the 3rd/4th trial sign-up??

I guess it's a "good" problem to have that people want to experience what we offer, but I need to implement a way to prevent this before we raise money, and this becomes an issue on a larger scale. 


Doc Waller
LYFE At Home, Founder & Creative Director



  • Comment author
    Pi Healthcare

    This doesn't help much, and you probably have it covered, but make sure your T&Cs cover those scenarios and don't be scared of putting out a warning shot to suspected abusers. I've done that in the past, and it has the desired effect 90% of the time. Of course, it's laborious and manual, though! I'd be interested to hear of any better option, but I'm not sure there is where real emails are concerned, short of vetting the trial requests!

  • Comment author
    Josh Lopez

    Hey Doc Waller 👋

    We have talked about this internally. Possibly having a way to prevent emails with the "+" to get around free trials. Please make a post in the Product Wishlist and we can talk about it further and you will be notified when the feature is available. I dont have an eta on this at the moment. I like the post from Pi Healthcare above!

  • Comment author
    John Matias

    Doc Waller

    One idea that comes to mind, would be to use form validation in webflow on the email form input. You could use the attribute: pattern="someregex" on that field to block anyone using any email with the "+" symbol. Basically what Josh said above but you could implement this yourself. I don't do this currently but I do use the pattern attribute to make sure that folks format their email address correctly. 

    I did a little quick Bing chat (only cuz ChatGPT was down) and it gave this answer:

    Sure, I can help you with that. A regex expression is a sequence of characters that defines a search pattern for text. The pattern attribute in HTML forms allows you to specify a regex expression that the input value must match in order to be valid.

    One possible regex expression for an email form input without the + symbol is:

    ^[a-zA-Z0-9_.-]+@ [a-zA-Z0-9-]+\. [a-zA-Z0-9-.]+$

    This expression means:

    • The input must start with one or more alphanumeric characters, underscores, dots, or dashes (^[a-zA-Z0-9_.-]+).
    • Then, there must be an @ sign (@).
    • After that, there must be one or more alphanumeric characters or dashes ([a-zA-Z0-9-]+).
    • Then, there must be a dot (\.).
    • Finally, there must be one or more alphanumeric characters, dots, or dashes ([a-zA-Z0-9-.]+$).

    This expression will match email addresses like or, but not or

    You can test this expression on various online tools, such as this one or this one.

    I hope this helps you with your task. If you have any other questions, feel free to ask me. 😊

  • Comment author
    Doc Waller

    Thank you for this suggestion! I'll take a deeper look at this today. Much, much appreciated!


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