Magento Commerce and Google Merchants UK VAT?

We have a Magento commerce store (running ve开发者_Python百科rsion 1.5.1.0) which has roughly 1800 products each with cost and retail price values entered into the database.

Using tax rules (we only sell to the UK) we have added 20% VAT to all products, so the VAT is calculated for us and shown to the customer during the checkout process. On the product pages the VAT is included in the price so it's basically just a breakdown during the checkout process.

We have started using Google Merchant Centre to submit our catalog to Google which in turns shows our products in the Google Shopping section. This is great and I have matched our Magento attributes to the Google Attributes.

The problem is, you can't add tax on Google Merchant Centre if you're outside of the US and our price column is excluding VAT. This means the price advertised on Google Shopping is excluding VAT but when the customer clicks through to our site the price is inclusive of VAT. This looks underhand and unethical in my opinion.

As our price column excludes VAT I don't know what the best way around this is. I would prefer not to have to update all of our prices to include VAT because that makes updating VAT changes (seemingly annual!) long winded.

Any help would be appreciated.

For anyone else who is having this problem and can't find the answer:

http://www.magentocommerce.com/boards/viewreply/212683/

Place the following code into line 283 of app/code/core/Mage/GoogleBase/Model/Service/Item.php :

// VAT multiplier hack.
$this->_setAttributePrice(false, 1.2 * $object->getPrice());