You cannot file a Self Assessment tax return online:
for a partnership
for a trust or estate
if you lived abroad as a non-resident
to report multiple ‘chargeable gains’, for example from life insurance
if you get income from a trust, you’re a Lloyd’s underwriter or a religious minister
Use commercial software or download other forms instead.
If you’re sending a tax return for the 2017 to 2018 tax year or earlier, get forms from the National Archives.