A:You’ll usually receive a letter from HMRC informing you that your company tax return is due. This is known as a ‘notice to deliver a company tax return’. If you have received this and you fail to file your return on time, your company will be subject to a flat rate penalty of £100. If you overrun by 3 months, you’ll be charged a further £100 penalty. If tax returns are consecutively late for 3 or more accounting periods, this penalty increases to £500 with an additional £500 charged if you file your return more than 3 months late.  These penalties escalate significantly the later you file your tax return.