Table:
| AT DECEMBER 31 | 2019 | 2018 |
| --- | --- | --- |
| Trade receivables not past due | 2,082 | 2,091 |
| Trade receivables past due, net of allowance for doubtful accounts |  |  |
| Under 60 days | 541 | 508 |
| 60 to 120 days | 232 | 304 |
| Over 120 days | 64 | 72 |
| Trade receivables, net of allowance for doubtful accounts | 2,919 | 2,975 |
Paragraphs:
CREDIT RISK
In many instances, trade receivables are written off directly to bad debt expense if the account has not been collected after a predetermined period of time.
The following table provides further details on trade receivables, net of allowance for doubtful accounts.
Question:
When are trade receivables written off directly to bad debt expense?
Answer: if the account has not been collected after a predetermined period of time