# Plan vs actual

Running plan and actuals on one ledger means both post to the same double-entry core, separated by the scenario tag — no copies, no drift. Planning modules read and write that ledger directly at PH-1; delta-scenario storage, where a plan inherits the actual base instead of holding its own rows, is on the roadmap.

- Source: [Ledgerbook glossary](/glossary/)
- Related: [Accounting data layer](/glossary/accounting-data-layer/), [Ledger of record](/glossary/ledger-of-record/), [Bitemporal ledger](/glossary/bitemporal-ledger/)