id = "ledger-a-mistake-is-reversed-never-erased"
title = "A reversal cancels an entry and leaves the original standing, and an entry is reversed only once"
rule = "A posted entry MUST NOT be changed or erased; a mistake MUST be corrected by an entry opposite to it, which MUST leave the original's lines as written, and an entry MUST be reversed at most once."
status = "AUTHORITY"
sources = [
  "Pacioli, Summa (1494), ch. 31: \"make another entry opposite this one\"; ch. 36: \"You should not write backward, but always forward\" (docs/spec/sources/pacioli-1494.md)",
  "Rev. Proc. 98-25 section 5.01: the audit trail (docs/spec/sources/irs-records.md)",
  "CHOICE, the owner, 2026-10-13 (docs/spec/rules.md B-10): a correction corrects once",
]
tags = ["accrual", "book", "us", "ledger", "reversal"]

[setup]
currency = "USD"
fiscal_year_start = "01-01"
basis = "accrual"
rounding = "half-even"

[[setup.accounts]]
code = "1000"
name = "Cash"
type = "asset"

[[setup.accounts]]
code = "2000"
name = "Loan"
type = "liability"

[[setup.accounts]]
code = "3000"
name = "Capital"
type = "equity"

[[setup.accounts]]
code = "4000"
name = "Sales"
type = "revenue"
tax_category = "gross_receipts"

[[setup.accounts]]
code = "6000"
name = "Rent"
type = "expense"
tax_category = "rent_property"

[[events]]
date = "2026-01-10"
description = "Rent paid twice by mistake"
lines = [
  { account = "6000", side = "debit", amount = "800.00" },
  { account = "1000", side = "credit", amount = "800.00" },
]

[[events]]
date = "2026-01-12"
description = "Reverse entry 1"
reverses = 1

# A second reversal of the same entry would take the 800.00 out twice.
[[events]]
date = "2026-01-13"
description = "Reverse entry 1 again"
refused = "already_reversed"
reverses = 1

# The original still reads as it was written: posted is forever.
[[expect]]
query = "entry"
entry = 1
[expect.values]
"6000.debit" = "800.00"
"1000.credit" = "800.00"

# The reversal is the original with its sides flipped.
[[expect]]
query = "entry"
entry = 2
[expect.values]
"6000.credit" = "800.00"
"1000.debit" = "800.00"

# Net of the two, nothing: as if nothing had been written (ch. 31).
[[expect]]
query = "trial_balance"
as_of = "2026-12-31"
[expect.values]
"1000" = "0.00"
"2000" = "0.00"
"3000" = "0.00"
"4000" = "0.00"
"6000" = "0.00"

# Before the reversal's date the original stands alone.
[[expect]]
query = "trial_balance"
as_of = "2026-01-11"
[expect.values]
"1000" = "-800.00"
"2000" = "0.00"
"3000" = "0.00"
"4000" = "0.00"
"6000" = "800.00"