*Use the 69 Code (US) / 1471 Code (UK)

In the US, dialing *69 allows you to call back the last number that called you, even if the number was private. This service provides details of the previous caller’s number and, if listed in a public database, their name and address. Some phone service providers may charge for this service.
In the UK, the equivalent service is dialing 1471. This service tells you the last number that called and can offer the option to return the call directly.