The collection of Q Codes shown here originally designed as abbreviations to speed up morse transmission.
Nowadays however they are commonly used throughout amateur, marine and aeronautical communications.
The most common Q codes used in Amateur Radio are highlighted in red.
Some codes can form part of a question and an answer, for example:
What is your QTH?
My QTH is London.
| Q Code | Meaning |
| QNA | Answer in prearranged order. |
| QNC | All net stations copy. |
| QND | Net is directed. |
| QNE | Entire net stand by. |
| QNF | Net is free. |
| QNG | Take over as net control station. |
| QNI | Net stations report in. |
| QNM | You are QRMing the net. |
| QNN | Net control station is [call sign]. |
| QNO | Station is leaving the net. |
| QNP | Unable to copy you. |
| QNS | Following stations are in the net. |
| QNT | I request permission to leave the net. |
| QNU | The net has traffic for you. |
| QNX | You are excused from the net |
| QNY | Shift to another frequency. |
| QNZ | Zero beat your signal with mine. |
| QRG | Will you tell me my exact frequency? |
| QRH | Does my frequency vary? |
| QRJ | Are you receiving me badly? |
| QRK | What is the intelligibility of my signals? |
| QRL | Is this frequency in use? |
| QRM | Is my transmission being interfered with? (M = Man made) |
| QRN | Are you troubled by static? (N = Natural) |
| QRO | Shall I increase power? |
| QRP | Low Power / Shall I decrease power? |
| QRQ | Shall I send faster? |
| QRS | Shall I send more slowly? |
| QRT | Closing down my station |
| QRU | Have you anything for me? |
| QRV | Are you ready? |
| QRX | When will you call me again? |
| QRY | What is my turn? |
| QRZ | Who is calling me? |
| QSA | What is the strength of my signals? |
| QSB | Are my signals fading? |
| QSD | Is my keying defective? |
| QSG | Shall I send messages? |
| QSK | Can you hear between your signals? |
| QSL | Can you acknowledge receipt? |
| QSM | Shall I repeat the last message? |
| QSN | Did you hear me? |
| QSO | Contact with a station / Can you communicate with me? |
| QSP | Will you relay? |
| QST | General call preceding a message. |
| QSU | Shall I send or reply on this frequency? |
| QSW | Will you send on this frequency? |
| QSX | Will you listen? |
| QSY | Shall I change frequency? |
| QSZ | Shall I send each word more than once? |
| QTA | Shall I cancel message? |
| QTB | Do you agree with my counting of words? |
| QTC | How many messages have you to send? |
| QTH | What is your location? / My location is ... |
| QTR | What is the correct time? |