Originally Posted by
6rugrats
I believe this poster responded to another poster who did not believe any country would ask for it, and thus, the information is relevant in this thread.
I know you've posted you were never asked for this, but I've been asked for it every time I've traveled alone to Canada and Mexico with my daughter. I was also asked for it in the UK this year. I don't believe a 17 year old will be asked for it anywhere.
Go read post #5.
If you regularly have problems with immigration officers, as you seem to be suggesting, perhaps there's something in your conduct raising a red flag? It is not the norm for the UK to request proof of custody, nor does the State Department website state that the UK requires such proof, which it does for the other countries mentioned, such as Mexico.