UK Vat change from 17.5 to 15% - How will this affect your code?

Question

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

Answer 1

I've a nasty feeling that 2 of the systems I've inherited have the rate hard-coded somewhere.

Worse than that is that if it is hard-coded, I will simply be replacing the hard-coded values as I don't have the time for properly changing it.

Even worse than that, I don't know where I'm going to get the time to actually do the change. So I imagine that it won't be done in time for Monday's change. Of course there are more interesting issues, such as that our £10 subscription is based on being £10 including 17.5% VAT (£8.515 or whatever it is). It'll now be £9.79 or so, making a complete mess of everything that advertises it at £10, and all the site calculations based on £10.

All this because the idiot in charge of the piggy-bank wanted a headline.