Yes, "Thank you for getting back to me" is considered a formal expression, and it is used when you want to express gratitude to someone for responding to you. It is a courteous way of acknowledging that the person has taken the time to reply or follow up on something.
You can use this phrase in various situations, such as:
Professional or business emails: When you receive a response from a colleague, client, or business contact, you can thank them for getting back to you.
Job applications or interviews: After a job interview or when receiving feedback on an application, you can use this phrase to show appreciation for the response.
Personal communications: In more formal or serious conversations, where you need to acknowledge someone's response, you can use this expression.
When waiting for information: If you had asked someone for information or clarification and they reply, thanking them for getting back to you is a polite way to show your appreciation.
Overall, "Thank you for getting back to me" is a polite and professional way to acknowledge someone's response, especially in a more formal setting. In casual conversations with friends or close acquaintances, you might opt for a more relaxed expression of thanks.