As many readers will no doubt be aware, Budget 2011 announced changes to Corporation Tax rates and allowances from 1 April 2011, including reducing the main rate of Corporation Tax to 26% and the small profits rate to 20%.

These changes will take effect from the date the Finance Bill 2011 receives Royal Assent (which is anticipated to be during July) but affect corporation tax returns for accounting periods ending on or after 1 April 2011, with filing dates of 1 April 2012 or later.

If a company has no tax liability and a business wishes to file its company tax return early, HMRC advises there is no reason not to proceed because the rate changes will have no impact.

However, if a company does have a tax liability, it will be necessary to wait to file the return until after HMRC's online service is updated in October 2011 with the new rates. If it is not possible to wait to file until October and a business has an urgent need to file before then, HMRC recommend that contact is made to the relevant HMRC Corporation Tax Office for further advice.