Incorrect Order Total Passed To Payment Module

[danrimer]

Hello

 

I don't know if this has been asked before... I have searched a great deal and come up empty, so I'm guessing not!

 

I have an intermittent problem where a customer's order total is different to the total requested from the payment module. If the customer proceeds, their order is highlighted as "Payment Error" and they are sent the usual email (and their order is not activated).

 

Sometimes the value is higher and sometimes lower. It is different by a couple of GBP and not just pence that could be written off.

 

The biggest problem is that I haven't been able to recreate the error. I've tried switching all the caching settings on/off including all the possible permutations to no avail.

 

Of course the customers have no idea if they have "done something" or if an error had occurred just before checkout etc!!

 

I have a log file being generated by the payment module and as expected, the amount is the same as the amount charged to the card and is different to that shown on the website! 

 

If anyone can help, I'd be really grateful!!

 

 

Cheers

 

Dan

[Daresh]

I had a similar problem once and it was all about rounding. Prestashop while calculating the shipping cost, doesn't take the rounding settings into account. But my errors were not in the whole GBP, but pences.

 

But maybe it will give you some clue, this thread helped me:

https://www.prestashop.com/forums/topic/382738-paypal-and-corrency-rounding/

Edited January 28, 2016 by Daresh (see edit history)

[danrimer]

@Daresh. Thanks for the info. I've found a fair few posts about rounding errors, but as you say, this is whole GBP!! Quite often a PayPal order doesn't add up correctly, but that's because the PayPal module does the addition itself (and sends the entire invoice to the PayPal customer).

 

I've received an order this morning for a dozen or so items. The customer was overcharged by £3.65!! The entire order only came to £20... I only have 1 item at £3.65 on my website and the customer did not even look at that item... So who knows what is going on!?