One record, with what is owed each way
A partner is not just a name and a phone number. Their record shows the balance and the movement behind it: what was invoiced, what was paid, what is outstanding — with a printable statement for when it has to be sent to someone.
It is the same data as the ledger, not a copy kept separately that eventually disagrees.
Import and deduplication
Contacts import from a file, and duplicates are resolved on their own screen. This is not occasional housekeeping: in any contact base that grows from several sources — import, website form, online order — the same person arrives more than once. Without somewhere to merge them, one customer's balance splits in two.
Connected, not isolated
The contact is the same object for invoices, contracts, projects and correspondence. What you see on their record is the real history of the relationship, not a list of notes.
Worth knowing
The most common problem in a customer base is not missing information but duplicated information: two records for the same company, each holding half the truth. That is why merging them is an operation in its own right rather than a manual delete.