Paypal Error 10426 – when coupon code is used

@wporgyvonne Can you confirm what kind of coupon is being used and its amount? Also, has any modification has been made to the number of decimals that are used? Meaning, is there any custom code that changes the number of decimals for rounding?

Thank you for replying Jesse. No custom code is added to round the decimals.
The coupon used is via woocommerce.

Replicating the issue:
Purchase two of this product (link here)
Apply coupon code DISCOUNT10

The amount is $66, with discount of $6.60, the final amount is $59.40

I have tried purchasing with difference price – one being $xx.15 with coupon and it was successful. Seems to only happen with certain value, which is odd.

Hi Jesse, I have reverted to Paypal Standard for my client while waiting for updates from your team.

Thank you

@wporgyvonne I’ve tried to replicate this, but I have not been able to.

I have set my taxes to be 15%, with my settings under WooCommerce > Settings > Tax as shown here:

Link to image: https://d.pr/i/TkTNFQ

My product has a price of 33, and then I add 2 to the cart and apply a 10% off coupon. The amounts are as shown below:

Link to image: https://d.pr/i/XYB2gw

The order goes through without any errors, you can see the amounts in the order here:

Link to image: https://d.pr/i/JjMXKG

Any chance you can clone the site and do a test with just WooCommerce and PayPal Checkout active to see if another plugin may be throwing off the rounding?

There’s a free plugin that allows you to clone through the admin area of the site: https://www.ads-software.com/plugins/wp-staging/

Hi Jesse,

Thank you so much for troubleshooting my case. Based on your detailed reply , I manage to figure out that it was the tax which caused the problem on my client’s website.

Kudos to you and team for helping out.