What has the speaker failed to locate?

The speaker has failed to locate his ID card. This situation typically arises when someone is in a hurry or needs to present identification for a specific reason, such as entering a secure area or boarding a flight. The emphasis on the ID card reflects its critical role in verification processes.

While the other items mentioned—wallet, keys, and phone—are important in daily life, the context surrounding the need for an ID card usually indicates a specific scenario where identification is required, highlighting the urgency of locating it. A wallet often contains several items including the ID card, and while keys and phones are crucial for accessing transportation and communication, the speaker's direct need for the ID card distinguishes it as the item he has failed to find.