where is 01245
UK area code 01245 is for Chelmsford in Essex, and the surrounding area. Locations using 01245 numbers include: 1  Boreham. 2  Broomfield. 3  Chelmsford. 4  Danbury. 5  Good Easter. 6  Great Baddow. 7  Hanningfield. 8  Hatfield Peverel.