Hi,
This threshold of £2000.00, applies when you are using the remittance basis to declare unremitted income from outside the UK.
Have a look at section 9 of RDR1
Guidance note for residence, domicile and the remittance basis: RDR1
The remittance basis must be reported in a self assessment tax return.
If you are not using the remittance basis, then you are using the 'arising' basis, which is the default method of taxation used in the UK.
Using the arising basis means that resident/domiciled or resident/not domiciled individuals, are taxable on their world-wide income in the UK.
This means that you do have to declare your foreign interest in a self assessment tax return and if any foreign tax is paid on the interest, you can claim a foreign tax credit relief (all in pounds sterling).
Your foreign and UK interest will be added together and the appropriate rate of relief applied, based on the level of your income.
Have a look at the guidance for tax on savings interest here
Tax on savings interest
Thank you