For those individuals who have previously submitted 'paper' self assessment tax returns the deadline for the 2016/17 return is 31 October 2017. Returns submitted after that date must be submitted electronically or they will incur a minimum penalty of £100. The penalty applies even when there is no tax to pay or the tax is paid on time.
If you would like any help with the completion of your return please do get in touch.
Internet link: GOV.UK deadline