The abbreviation "BTY" is commonly used in text messages and chats, and it stands for "back to you." There are a few common synonyms for this phrase that can be used to convey the same meaning. For example, "returning the favor" is often used to indicate that someone is responding to a previous action or message. "Getting back to you" is another common way of saying that someone will respond to a message or request. Similarly, "reverting" can be used to indicate that someone is returning to a conversation or topic that was previously discussed. Overall, these phrases can be used interchangeably with "BTY" in most informal contexts.