Magento 1.7 CE- Tax calculation is totally incorrect
We are migrating from Prestashop to Magento and used cart2cart to migrate.
Just testing now and Magento does not seem to add tax to the grand total even though this has been set.
1) Subtotal £14.98
2) Grand Total Excl. Tax £9.98
3) Tax 2.50
4) Grand Total Incl. Tax £12.48
Tax is 20% and the subtotal includes tax. But the grand total 4) seems to not include tax, even though set in admin. The tax of £2.50 is correct and the grand total 3) seems to have been calculated by 4) - 3)
We can get it to work by selecting in admin>tax> Apply tax before discount. However whenever a discount is used the tax figure would be wrong.
Tried deleting and setting up tax rates again, imported all catalog prices to include vat, rounded down to 2 decimal places. This seemed to have worked however it may have just been the action of backing up and maintenance mode.
Now it is back to the above example again after installing a loyalty reward module. Tried disabling that in admin and no effect.