Police are advising residents that only one number will be available from September to report a non-emergency.
The current 101 number should be used to report crimes that have happened, suspicious activity or to get some advice from a neighbourhood officer.
Now police are putting across the message that old lines which begin 03456 or 08456 will be switched off from September 1.
Chief Superintendent Laura Young, from the communications department, said: “We’ve been running several telephone lines for non-emergency calls to the police for well over a year as the 101 number got bedded in.
“Now we have decided the time is right to switch off old numbers and we want to make sure the public are aware of this before September.
“Anyone who does ring a number beginning 03465 or 08456 until September 1 will get a recorded message explaining the number is no longer in use and that 101 is the number to call, but they will still be put through to the police.
“The 101 number is certainly easier to remember. But in an emergency, if a life is at risk or a crime is happening, ring 999. For everything else, 101 is the number to use.”