threshold requiring income tax?

I am employed full time in the UK as scientist but occasionally get offered the possibility of a honorarium (£50-200) for giving presentations or reviewing documents, often from overseas. Is there a maximum amount I can accept before I will need to file income tax return on this or is this required for any amount that I potentially receive? thanks

Hi

If you have income from overseas for any amount then you would need to register for self assessment in order to report this.

Please see guidance here regarding foreign income and self assessment criteria:

Tax on foreign income

and  

Self Assessment tax returns

Thankyou.

Regards.