title: UK Vat change from 17.5 to 15% - How will this affect your code?
body: <p>The UK VAT system is changing from 17.5% to 15%. What strategies have you used in your code to store the VAT, and how will the change affect your applications. Do you store a history of vats so you can calculate old prices, or are old invoices stored in a separate table? Is it a simple config setting, or did you bodge it? What's the ideal way to store VAT?</p>