Goodwill is not amortized under either framework (a private-company election aside under US GAAP) and is tested for impairment at least annually — but the unit of account and the test mechanics differ.
| Area | US GAAP (ASC 350) | IFRS (IAS 36) |
|---|---|---|
| Unit of account | Reporting unit | Cash-generating unit (CGU) or group of CGUs |
| Test | Single-step (post-ASU 2017-04): impairment = carrying − fair value of the reporting unit | One-step IAS 36: carrying vs recoverable amount of the CGU |
| Amortization | No (private companies may elect to amortize) | No |
| Reversal | Prohibited | Prohibited (for goodwill) |
| Frequency | Annual + on triggers | Annual + on triggers |
The reporting-unit vs CGU difference, and the single-step (reporting-unit fair value) vs IAS 36 recoverable-amount mechanics, can produce different impairment conclusions for the same business.
An educational reference and original synthesis — not investment advice, and not a substitute for the standard or for professional accounting guidance. For authoritative measurement detail, consult ASC 350 / IAS 36 directly.