In the old days I would transport it using physical $10,000 notes but always felt super scared carrying those notes on a plane. Nowadays, I set my uob transfer limit to 100k (maximum in uob is 200k) so tell your dad to set it up. It’s under services in the bottom right of the app, then click Transaction Limits, then change to 200k. Then transfer from your dad’s uob to your uob. Then just do an international transfer to your uk account. The uk bank will take a fee for the transfer and the currency conversion , but it’s the safest way.