What does “Transposition error” mean in bookkeeping?

Transposition error: Two digits typed the wrong way round, such as 1,320 entered as 1,230. The difference always divides evenly by 9, which is a quick way to spot one.

Example$1,320.00 − $1,230.00 = $90.00, and 90 ÷ 9 = 10.

Written for US bookkeeping. Last reviewed November 5, 2026. See all 100 terms.