If you are running a VAT enabled ubercart website in the UK, then you will no doubt be aware of the rate change to 20% on 4th January 2011. Are you also aware that some shipping services including some Royal Mail services will also be subject to VAT from 31st January 2011?
The change of VAT rate is easily handled by your ubercart website - just go to /admin/store/settings/taxes and change the rate to the new rate of 20%. If you are habitually entering prices including VAT when creating products, then you might want to check /admin/store/settings/taxes/vat first and use the option to "Keep VAT inclusive prices the same after a rate change".
Charging VAT on some postal services and not on others is not so easy - if you find yourself in this position (check the link to Royal Mail above), you'll need some thought and work to make your site compliant. Get in touch straight away as there is not an easy solution and not much time to remain VAT compliant.