I am using the Paypal standard (HTML 'API') to integrate Paypal to my website.
I have managed to display 'subscribe' buttons for recurring payments, using HTML variables as specified in the Paypal documentation. However, there is one serious "show stopper" problem:
I am unable to get Paypal to recognize sales tax amount for RECURRING PAYMENTS.
Despite using the 'tax' field (and setting a positive number to it), the tax is not being displayed on the bill for the recurring item.
Using the 'tax' field for a 'buy now' button does however work correctly (the tax amount is shown on the bill page). Has anyone else experienced this - and what is the solution (or work around for this?)
BTW, I am running in the Paypal sandbox
Presently sales tax not supported for PayPal subscription buttons. It has been submitted as a requested feature.
I am just looking at the PayPal Subscriptions and have just realise this as a possible issue. As a work-around, the subscription amount could just be the total subscription amount including any taxes. An invoice with the breakdown of taxes will just need to be issues outside of PayPal.
来源：https://stackoverflow.com/questions/1620071/paypal-html-integration-problems-sales-tax-not-showing-for-recurring-payment