A real double-entry ledger

Sales, purchase, receipt, payment, contra, journal, credit and debit note, each posting through one code path with one set of rules. A voucher that does not balance is rejected before it reaches the database — and rejected again by the database, because the constraint is not something an application bug can talk its way past.

Each company keeps its own chart of accounts, numbering series, financial years and opening balances. Every query is scoped to your business, and an id that belongs to somebody else is answered as if it did not exist. Row-level security in the database adds a second lock on writes and on posting today; extending it to every read is in progress.

Allocate a line to a cost centre or a project and see the same figure by department, project or branch. Budgets are compared against the same postings the statements use — never against a separately maintained plan.

Closing a period locks it. Posting into a closed period is refused, not warned about; correcting one is an explicit reopen with a reason, recorded in the audit trail. A close that a determined user can post through is not a close.

A posted voucher is never edited. It is corrected by a reversal, a credit or debit note, or a fresh journal, and reversing one also reverses what it caused — the bill allocations it consumed and the stock it moved — so the ledger and the stock report keep agreeing.