There are tax penalties for Self Assessment (SA) tax returns and for late payment of tax due under SA.
The late filing penalty system changed for returns and payments from the 2010/11 year onwards.
A key feature of the new regime is that the late filing penalty is not reduced if the tax is paid on time.
There are no changes to late payment penalties. Interest is charged on both unpaid tax and unpaid penalties.
| Late filing | Late payment | Penalty |
| Cross filing deadline | – | £100 |
| ” | 30 days late | 5% of the tax due |
| 3 months late | – | Daily penalty £10 per day for up to 90 days (max £900) |
| 6 months late | – | 5% of the tax due or £300, if greater |
| 6 months late | 5% of tax outstanding at that date | |
| 12 months late | – | 5% or £300 if greater, unless the taxpayer is held to be deliberately withholding information that would enable HMRC to assess the tax due. |
| ” | 12 months late | 5% of tax outstanding at that date |
| 12 months & the taxpayer deliberately withholds information | – | Based on behaviour:
|