Title: Error: Invalid payment amount (again)
Last modified: June 5, 2026

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# Error: Invalid payment amount (again)

 *  [elmonty](https://wordpress.org/support/users/elmonty/)
 * (@elmonty)
 * [2 days, 21 hours ago](https://wordpress.org/support/topic/error-invalid-payment-amount-again/)
 * My users are again experiencing an “Invalid payment amount” error. Here is the
   form export: [https://pastebin.com/raw/uPt6mrDt](https://pastebin.com/raw/uPt6mrDt).
   I updated to Forminator version 1.54.0 and we still have this issue.
 * The current user experiencing this has entered simply 100 in the “Donation” field.
 * It seems that every time I update this software, something breaks.

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Plugin Support [Patrick – WPMU DEV Support](https://wordpress.org/support/users/wpmudevsupport12/)
 * (@wpmudevsupport12)
 * [2 days, 13 hours ago](https://wordpress.org/support/topic/error-invalid-payment-amount-again/#post-18930357)
 * Hi [@elmonty](https://wordpress.org/support/users/elmonty/)
 * Sorry to hear you are having this issue.
 * I was able to replicate the problem around the issue on my lab site but we also
   tested on other websites and it isn’t happening.
 * I believe the problem is around the calculation. Could you duplicate the form,
   remove the paypal field and submit it without the payment field, then go to wp-
   admin > Forminator > Submissions and locate the submission, check the total value,
   will it show 103 or 104? ( considering only the donation + super charge 3.5 ).
 * In short, the “(0+0}+100)*((3.5/100)+1)” is 103.5, using round it the front end
   seems to be rounding to 103 while backend to 104 therefore invalid payment amount.
 * I also escalated this to our second line support team, once we hear back from
   the second line support team we will let you know.
 * Best Regards
    Patrick Freitas
 *  Plugin Support [Patrick – WPMU DEV Support](https://wordpress.org/support/users/wpmudevsupport12/)
 * (@wpmudevsupport12)
 * [2 days, 13 hours ago](https://wordpress.org/support/topic/error-invalid-payment-amount-again/#post-18930370)
 * Hi [@elmonty](https://wordpress.org/support/users/elmonty/)
 * An update here
 * Could you please let us know if you are using PHP 8.4 or lower versions?
 * The problem seems because a difference between PHP 8.3 to 8.4 when round happens
   to down vs up ( [https://stackoverflow.com/a/79816702](https://stackoverflow.com/a/79816702)),
   if you are using 8.3 or lower, please try updating to PHP 8.4.
 * I understand that front end via JavaScript the calculation seems correct and 
   I also reported it to our second level support, but in the meantime the PHP 8.4
   solution would fix the issue.
 * Best Regards
    Patrick Freitas

Viewing 2 replies - 1 through 2 (of 2 total)

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 * 2 replies
 * 2 participants
 * Last reply from: [Patrick – WPMU DEV Support](https://wordpress.org/support/users/wpmudevsupport12/)
 * Last activity: [2 days, 13 hours ago](https://wordpress.org/support/topic/error-invalid-payment-amount-again/#post-18930370)
 * Status: not resolved