Budgets can be setup for a specific customer, meaning that it will be a budget designated for that customer's use. The allocation of funds and budget depletion are all done on the contact level though (ie. A budget can be assigned to the customer but it will be associated with the customer's contact on the order level. If a contact is not assigned to the order, or budget access hasn't been granted to the contact, a budget cannot be added on the order item).
Budgets on the Customer
From the Edit Customer modal, a Customer can be assigned specific budgets or a new budget can be created specifically for them.
All of the contacts for this customer can then be manually assigned or automatically granted access to these budgets.
Note: A contact can be granted access to a budget without it having been assigned to the customer.
Budgets on the Contact
A Contact can be assigned access to specific budgets through the Edit Customer modal or from Settings > Customer > Budgets.
A default budget can be selected and will automatically be used when orders are placed for this contact.