BA:
https://www.britishairways.com/en-us/executive-club/household-accountsHousehold accounts can have up to seven members of any age.
Any member of the household (over 18) can redeem and it’ll be deducted evenly across all accounts.
Members can be added or leave a household account every 6 months.
A big caveat is that household accounts can only redeem points for members of the household, of from a “friends and family” list which can include 5 names per member (so in theory you can get 35 people on the list, you can just add more names to your household account and book through there).
Jetblue:
Between 2 and 7 members.
No age restrictions on Pool Members.
Pool Leaders must be 21 years of age or older.
Members must contribute 100% of their points to contribute to the pool.
Members will still have access to redeem their individual balance while contributing to the pool.
Members can leave the pool with their remaining balance of unused points.
Pool Leader can designate other members in the pool to redeem from the pooled balance.
Air Canada:
Max pool size: 9. Allows adding up to 8 additional members (controlled by lead who can invite and member accepts).
How to add: Adding done online.
How to remove: Call-in. Rep said that they need to fill out a form to request it, and it could take a week or so, but when we asked to add someone else (above limit) was able to get an exception from supervisor and have member removed instantly.
Restrictions: None that I'm aware of.
KLM/Air France:
Two adults + six children
25% discount on childrens award tickets
childrens miles do not expire.
members can leave the group after 6 months. child turns 18 automaticly removed from group if there are already 2 adults in the group
The family leader can transfer miles between family member,
which resets all miles expiery date