If you look at the T&C's for EE unlimited data:
EE Terms and Conditions
you will see the folloiwng wording:
The following terms apply to customers who have taken a Pay Monthly handset or SIM plan with an
unlimited data allowance since 28th August 2019.
Your inclusive data allowance is for personal, non-commercial use when in the UK and in the EU.
If you regularly tether 12 or more devices, we will consider this non-personal use and have the right
to move you to a more suitable plan.
We will consider usage above 600GB per month to be non-personal use and have the right to apply
traffic management controls to deprioritise your mobile traffic during busy periods, or to move you
to a business plan.
If you run your account you can gift up to 100GB of your data to others on your account. Data usage
on an unlimited plan will decrement from giftable allowance. Any data boost allowance will be
added to the giftable allowance.
A 50GB fair use policy applies outside UK
