I changed the shipping module last night in case the problem was coming from the Royal Mail shipping module. I used the 'Duplicate Table Rate' module to create a secondary table rate and entered the cost details from Royal Mail. When i did this, i realised that the Royal Mail shipping module automatically adds a £0.70 handling charge, which is where the unknown numbers were being generated.
So, the new shipping module is set up as follows:
Name: UK Royal Mail First Class Recorded
Enable Table Method
True
Shipping Table
0.1:1.79, 0.25:2.08, 0.5:2.54, 0.75:3.08, 1.0:3.62, 1.25:4.95, 1.5:5.70, 1.75:6.45, 2:7.20, 2.25:7.95, 2.5:8.70, 2.75:9.45, 3:10.20, 3.25:10.95, 3.5:11.70, 3.75:12.45, 4:13.20, 4.25:13.95, 4.5:14.70, 4.75:15.45, 5:16.20, 5.25:16.95, 5.5:17.70, 5.75:18.45, 6:19.20
Table Method
weight
Handling Fee
0
Tax Class
VAT
Tax Basis
Shipping
Shipping Zone
UKALL
Sort Order
500
The zone UKALL comprises all UK states, but does not have a tax rate attached to it. Instead, there is an EEC zone which includes the UK and all other countries in the EEC and applies tax to that. I don't know if this is important, but thought it was worth mentioning.
The new error log generated this morning is as follows:
[ITEMAMT] => £289.00
[HANDLINGAMT] => £45.88
[SHIPPINGAMT] => £22.37
[TAXAMT] => £42.55
[AMT] => £308.04
From sale details as follows:
Sub-Total: £289.00 (£245.96 + £43.04 tax)
Shipping: £19.04 (£16.20 + £2.84 tax)
Tax @ 17.5%: £45.88 (£43.04 + £2.84)
Total: £308.04
So, PayPal is taking the item amount OK.
It is taking the tax as the handling amount.
It is adding an extra tax of 17.5% to the shipping amount (£16.20*1.175=£19.04*1.175=£22.37. £22.37-£19.04=£3.33).
It is then subtracting that extra portion of the double shipping tax from actual tax amount (£45.88-£3.33=£42.55) and making that the tax amount.
Obviously, the totals then don't match.
I would really appreciate some help on this as i really can't see what i could be doing wrong at my end and i am losing sales every day because of this problem.
Thanks.



