If you submit your tax return on paper, the return is due to the Revenue by 31 October following the tax year end.
If you submit your tax return electronically, the return is due to the Revenue by 31 January following the tax year end.
If you do not submit your tax return by these deadlines, the Revenue will issue penalties, depending on how long the return remains overdue. The first penalty of £100 is applicable as soon as the return is one day overdue, regardless of the level of tax owed, if any! These penalties increase, depending on how long the return is overdue. There are also tax related penalties, which are calculated based on the amount of time late and the amount of tax unpaid.
Corporation tax returns are due to the Revenue 12 months after the year end while the tax payment is due 9 months and 1 day after the year end.
Failure to submit your return will result in penalties, commencing at £100. Interest will be charged at the Revenue’s current rate on any late paid tax.
This area is where the Revenue has increased the penalty regime, by making penalties payable if you miss submitting or paying your monthly (or quarterly, if applied for) PAYE/NI amounts. These penalties commence at £100 and could rise to substantial amounts if you seriously delay paying your PAYE/NI. The penalties and interest are based on the amounts due for the relevant period.
There are also penalties linked to the filing of the year end annual returns, P35 and P11ds, based on how late they are, and if they are incorrect.