"When responding to calls from Air Traffic Control (control tower or a regional facility) what is the correct response? Do you repeat everything back to them with your call numbers? I hear some only repeat a portion while others repeat everything back to the controller. What does ATC prefer?" - Gregory R.
“You should read back pertinent information and instructions containing altitude assignments, vectors, runway assignments, etc. The read back of the numbers serves as a double check between pilots and controllers and reduces the kinds of communications errors that occur when a number is either misheard or is incorrect.
Read back the numbers in the same sequence as they are given in the clearance or instruction (from ATC).
Include the aircraft identification in all readbacks and acknowledgments. This helps controllers to determine that the correct aircraft received the clearance or instruction. The requirement to include aircraft identification in all readbacks and acknowledgments becomes more important as frequency congestion increases and when aircraft with similar call signs are on the same frequency.
Initial read back of a taxi, departure or landing clearance should include the runway assignment – including left, right, center if applicable.
The same with frequency changes or transponder codes – read back the numbers but keep it short and simple. For example, if the controller instructs you to contact the tower on a certain frequency, you do not need to read back the words Contact the tower… simply say Tower 120.3, Cessna Five One Eight.
Always use your call sign to end the transmission.”