From 1 April 2011, all payments of corporation tax must be made electronically. In this sense, HMRC count a payment made at your bank, building society or participating post office using a HMRC payslip as ‘electronic’.
This means that paying corporation tax by cheque 'in the post' is no longer an option.
If the Revenue really are so arrogant to return cheques sent in the post, we will certainly hear about it!
More information is available from:
http://www.hmrc.gov.uk/payinghmrc/corporationtax.htm
UPDATE - FEBRUARY 2015
This initiative was issued in April 2011. In our original blog, we made the point that it was highly unlikely that HMRC would return cheques sent in the post. In February 2015, it looks like HMRC are still accepting cheques, despite their best efforts to make everyone operate electronically.