Changing VAT to 15% in OSCommerce

OSCommerce and its derivative CRE Loaded are popular open source ecommerce engines.
This mini-HOWTO explains how to change the Value Added Tax (VAT) rate from 17.5% to 15% for the UK, in line with Alistair Darling's pre budget report (PBR). To recap:
The standard rate of VAT will reduce from 17.5% to 15% with effect from 1/122008. The 15% rate will have effect for:

• Supplies of goods and services made on or after 1/12/2008.
• Imports on or after 1/12/2008.
• Acquisitions of goods from other EU States on or after the same date.

The standard rate of VAT will revert to 17.5% with effect from 1 January 2010.

Changing the VAT rate from 17.5%

1. Log into OSCommerce's admin control panel, typically this is under http://yourdomain.com/admin/index.php
2. Click on Locations/Taxes and choose the Tax Rates menu item
3. Locate the current 17.5% rate(s). N.B. you may have more than one rate if you charge VAT on delivery.
4. Select the tax rate you want to work with by clicking on it, to ensure its highlighted, then click the Edit button on the right.
5. Amend the tax rate from 17.5000 to 15.0000 and the correspodning description.
6. Click the update button.
7. Repeat for other rates.
   

Tips on changing the VAT rate to 15%

• Previous transactions are unaffected and will continue to show VAT at 17.5%
• Unfortunately OScommerce does not provide an auotmatic way to switch over the VAT rate at 1 second past midnight. Technically it possible to setup a Cron job to update the database at this time. Realistically it is probbaly easier for shop owners to stay up Sunday night!
• Don't forget to check other shop assets, such as artwork, that may contain the 17.5% rate.
• The fraction 40/47 - currently used to work manually out the net figure by applying it to the gross figure. This fraction changes to 20/23 from 1st December.