Few things I think need to be added to with the joint account:
Ability to request money from your personal account on either side of the account. For example if we go shopping and I decide to buy something for myself I can just request the amount from my account to avoid paying in two separate transactions or sending it proactively.
Ability to schedule a payment to the joint account without having to use the account number and sort code. This is only a minor annoyance
Ability to add money into the joint account pots so we have a joint holiday pot but at the minute we have to transfer the money into the joint account. Then then move it again within the joint account tab.
The main issue with implementing this seems to be how to display both the joint and personal accounts for every Monzo contact when someone is going to split a bill.
I think the best solution would be to still have Bill Split requests go to personal accounts, but then to have an option to “Pay with Joint Account” or “Pay with Other Account” inside the request feed item.
Other Joint Account Bill Split improvements
You can vote for money received from splits sent from joint accounts to go back into your joint account, instead of your personal account, here:
You can vote to Bill Split with your own joint/personal account here: