Ok newbie here so patience please 
I want my son to be able to use Xbox Live on two consoles - one at his mum's and one at my house. I've redeemed the code under my Xbox account - so does that mean he has to have me signed in on the console which he wants to use Xbox live on?
There doesn't seem to be any way to give a 'child' so to speak an Xbox Live account. If I tried to redeem the code under his account it wouldn't let me proceed because he's too young to enter a payment method or use reoccurring billing.

I want my son to be able to use Xbox Live on two consoles - one at his mum's and one at my house. I've redeemed the code under my Xbox account - so does that mean he has to have me signed in on the console which he wants to use Xbox live on?
There doesn't seem to be any way to give a 'child' so to speak an Xbox Live account. If I tried to redeem the code under his account it wouldn't let me proceed because he's too young to enter a payment method or use reoccurring billing.