Magento: PayPal Website Payments Standard not displayed

I am having problem in displaying PayPal payment method in payment method section of onepage checkout in Magento.

I am using "PayPal Website Payments Standard".

I have enabled this module from backend (System -> Configuration -> SALES -> Payment Methods -> PayPal Website Payments Standard).

I have also entered the Business Name and Business Account at "Website Payments Standard" (System -> Configuration -> SALES -> PayPal Accounts -> Website Payments Standard). I have set Sandbox Flag = Yes and Debug Flag = Yes. I am using Sandbox business name and account.

After doing all this, I think I should see the PayPal payment method option in my Checkout page on Payment methods section. But PayPal payment option is not displayed there.

Cause:

The possible cause is because base currency of your shop is not supported by PayPal.

Solution:

PayPal supports the following currencies:-

protected $_allowCurrencyCode = array('AUD', 'CAD', 'CZK', 'DKK', 'EUR', 'HKD', 'HUF', 'ILS', 'JPY', 'MXN', 'NOK', 'NZD', 'PLN', 'GBP', 'SGD', 'SEK', 'CHF', 'USD');

The above code is present in the class Mage_Paypal_Model_Standard. You can add your shop's base currency code to the array.

Like, I have base currency code as NPR. To show PayPal payment method in my shop, I need to add NPR in the array. Like the following way:-

protected $_allowCurrencyCode = array('AUD', 'CAD', 'CZK', 'DKK', 'EUR', 'HKD', 'HUF', 'ILS', 'JPY', 'MXN', 'NOK', 'NZD', 'PLN', 'GBP', 'SGD', 'SEK', 'CHF', 'USD', 'NPR');

Now, PayPal payment option is displayed in payment methods section of onepage checkout.

And, to change the data sent from your site to paypal, you have to modify getStandardCheckoutFormFields()function of Mage_Paypal_Model_Standard class. This function returns an array ($rArr) with some necessary parameters. You need to change the value of 'currency_code' and 'amount' of the array. Currency_code can be any currency code that is supported by PayPal and Amount must be converted from your base currency to that particular currency code.

Hope this helps. Thanks.