Which HTTP method is better to use for retrieving data by phone number: GET or POST?

To obtain data by phone number, it is preferable to use the GET method, as it is intended for requesting information without changing the server's state. GET requests pass parameters in the URL, which is convenient for identifiers such as phone numbers.

However, if the phone number contains sensitive data or is long, it is better to use POST to pass parameters in the request body and not expose them in the URL.

Example of a GET request:

GET /api/user?phone=+71234567890 HTTP/1.1
Host: example.com

In summary: if the data is not sensitive and short — use GET; if there are security or volume requirements — use POST.