The caller ID feature requires batteries to work, batteries are not included.  I did put batteries in, and test it.

The GE 29267GE3-B is a corded landline phone with a sleek silver and black design. This trimline phone features call waiting and caller ID capabilities, providing convenient communication options for home or office use. The phone has one phone line cord and is designed as a unit for easy setup and use. With the GE brand reputation for quality and reliability, this corded phone is a practical choice for those looking for a reliable communication device.