HMRC Admin 21 Response

Hi Alisa,
Please have a look at article 15 of the UK / Portugal tax treaty (UK/PORTUGAL INCOME TAX CONVENTION SIGNED 27 MARCH 1968).  It advises that your employment in the UK is taxable in the UK, while you are in the UK carrying out that employment.  You will be entitled to personal allowances to set against the income.  You would complete a P46 when commencing your employment.  Portugal can also tax this employment, so you would have to claim a credit for any UK tax payable.
Thank you.

Hi Antnisty,
Statutory maternity pay is taxable income and sould be declared under other state benefits.
Thank you.

Hi hgough,
That is correct.
Thank you.

Hi samuelkfp2000,
This would be interest.
Thank you.

Hi maxb,
You only need to show if you have exceeded the annual allowance and if a tax charge is due.
Thank you.

Hi Rodney,
The residence section of the tax return is not supported by HMRC software and you will need to purchase 3rd party - Self Assessment commercial software suppliers. the whole return must be submitted together.
Thank you.

Hi paszczaqp Tom
You will declare this hobby income as self employment so when completing the tax return you will have 2 self employment sources.
Thank you.

Hi Sascha,
If you are tax resident and domicile then yes. if claiming the remittance basis it depends on whether you remit the incme to the UK. please refer to Paying tax on the remittance basis (Self Assessment helpsheet HS264)
Thank you.

Hi Andrew,
No. unused allowances cannot be backdated, they can only carry forward. 
Thank you.

Hi eymw,
Please refer to Self Assessment tax returns.
Thank you.