24-03-2018 06:04 PM - edited 24-03-2018 06:05 PM
Yes, but only if they are 2 lines running on the same EE account i.e. both lines are on the same monthly EE bill.
They can either be handset or mobile broadband plans, however, you cannot gift data from/to home 4GEE plans unfortunately.
24-03-2018 06:12 PM
Please take a look at the data gifting help article to find out everything you need to know.