Is the payment method being stored for each trade or per account?

North Capital retains the information to be able to return funds to the originating account.

Example:
- user makes purchase 1 with a linked account - bank account 1
- user makes purchase 2 using a different account - bank account 2
 
The bank account will be replaced for the user (Account), but what about the purchase (Trade)? 
Will purchase 1 be considered as paid with bank account 2 just because it had replaced bank account 1?
 
North Capital retains the information to be able to return funds to the originating account. In the example provided, the purchase 1 would be considered to be paid with bank account 1.