Small Honorarium from USA Academic Institution

Hiya, I'm a UK citizen, living in the UK, I'm payed PAYE at an academic institution here. A USA academic research project wants some very limited consultation and has offered me a $3000 USD honorarium for providing them advice and support. Questions: 1) Do I need to file self-assessment in the UK, as I'm not sure it is worth the stress of me doing that for $3K USD that is then taxed. 2) If I ask the USA institution to withhold tax, do I need to do anything here in the UK? (i.e. I've already paid tax there, so don't need to do so here) If doing that would I need to somehow submit a tax form in the USA?! 3) What is the easiest way to receive some of this money without having to change my tax assessment here in the UK. (I want to continue PAYE and not submit additional forms if possible.) Thanks for any suggestions.

Hi,
Honoraria are liable to Income Tax and National Insurance in the same way as the payment of wages or salaries. Straight forward reimbursement of out of pocket expenses will not attract Income Tax. You can see guidance and examples here:
Employment status
EIM71130 - Voluntary office holders: meaning of reasonable: examples
Thank you.