Telephone changes affecting anyone with an 01908 area code will take effect from Wednesday.
From September 30, anyone calling a Milton Keynes number from another local landline will have to enter the 01908 area’s code too.
Callers who omit the 01908 code when dialling locally will not be connected, and will instead hear a message telling them to redial and include the code.
The price of making local calls is not affected by dialling the code.
Telephone bosses at Ofcom say the change will help the network to cope with the increasing number of landlines in the Milton Keynes area. In future new number will be freed up with the first digit after the area code a 0 or 1.
For more information visit ofcom.org.uk/dialthecode