HM Revenue and Customs set time limits with penalties for receiving late tax returns or payments. You must pay any money owed for the Self Assessment deadline 2017/18 to avoid a penalty.
SELF ASSESSMENT DEADLINES 2018: The most recent 'full' tax year started on the 6th of April 2017 and it ended on the 5th of April 2018.
Note: Making advance 'payments on account' can extend the Self Assessment deadline to the 31st of July.
As a rule, there are penalties for sending in late tax returns and payments. In some cases you can appeal against a penalty if you disagree with a tax decision and have a reasonable excuse.
HM Revenue and Customs use an automatic process to collect taxes from wages and pensions. But, your tax code must qualify and you must submit an online return before the December 30th deadline.
They do not accept a return online for a trustee of a registered pension scheme or a non-resident company. Thus, send in your paper tax return before the deadline of January the 31st.
Note: In some cases HMRC may send you an email or write to you setting up a different date for the deadline.
Special tax return rules apply to partnerships with accounting dates between the 1st of February and the 5th of April. If one of the partners is a limited company then the deadline dates are different for:
Self Assessment tax return deadlines have already passed for 2016/17 and earlier. You must still send in a tax return or payment for these previous dates - without delay. But, there will be a penalty for a late tax return or bill payment.
Those who need to send a tax return will get penalized for missing the deadline. Penalties apply for submitting it late or not paying the bill on time.
Filing a late tax return will result in a penalty of £100 providing it gets filed within three (3) months after the SA deadline. The penalties for late tax returns increase if it is more than 3 months late or the tax bill gets paid late.
Note: You can get an estimate of the penalty for Self Assessment tax returns more than 3 months late. The same online tool gives and approximation for late payments. A penalty applies to all partners if a partnership tax return gets filed late.
UK Self Assessment Tax Return Deadlines and Penalties