Complete - Tax Calc Error?
Posted: Tue Jul 01, 2008 1:56 am
Hi All,
Not sure if this is a well-known error or not, but we've just come across a potentially big problem with the calculating of discounts on invoices.
As standard, the invoices table calculates the sub total, then the tax total, then subtracts and discount and adds any shipping.
BUT - the discount is removed without taking into account the tax on that discount, so the tax (VAT in our case) amount, and therefore the total amount is wrong.
Example:
Sub total: £250 (in this case, all subject to 17.5% VAT)
Discount total £50 (in this case generated by a 20% discount rate)
Tax total: £43.75 (WRONG, should be 17.5% of £200, not 17.5% of £250)
Luckily, we noticed this before sending out too many new invoices, but could have been a bit embarrassing further down the line!
Is this just an error, or perhaps do we work out our tax amounts in a different way over here??
BTW - I've solved it so far by amending the InvTaxCalc field to subtract (discount total multiplied by the tax rate) from the tax total (We don't ship products, so I'm free to not worry about that box, which would have the same issue I would think). It seems a fairly simple solution, but I'm always worried that a simple change to a calc will trip me up later on - any thoughts?
Otherwise, excellent solution, very very impressed how easy it's been to get us up and running with the main modules whilst still developing add-ons for our own use.
Thanks, Matt
Not sure if this is a well-known error or not, but we've just come across a potentially big problem with the calculating of discounts on invoices.
As standard, the invoices table calculates the sub total, then the tax total, then subtracts and discount and adds any shipping.
BUT - the discount is removed without taking into account the tax on that discount, so the tax (VAT in our case) amount, and therefore the total amount is wrong.
Example:
Sub total: £250 (in this case, all subject to 17.5% VAT)
Discount total £50 (in this case generated by a 20% discount rate)
Tax total: £43.75 (WRONG, should be 17.5% of £200, not 17.5% of £250)
Luckily, we noticed this before sending out too many new invoices, but could have been a bit embarrassing further down the line!
Is this just an error, or perhaps do we work out our tax amounts in a different way over here??
BTW - I've solved it so far by amending the InvTaxCalc field to subtract (discount total multiplied by the tax rate) from the tax total (We don't ship products, so I'm free to not worry about that box, which would have the same issue I would think). It seems a fairly simple solution, but I'm always worried that a simple change to a calc will trip me up later on - any thoughts?
Otherwise, excellent solution, very very impressed how easy it's been to get us up and running with the main modules whilst still developing add-ons for our own use.
Thanks, Matt