Fire/EMS Unit Numbering:

ESN Based Station Numbers:

10 - Bethlehem Fire / EMS
11 - Fountain Hill Fire / EMS (dispatched by Lehigh County as Station 34)
12 - Freemansburg Fire
13 - Hellertown Fire / EMS
14 - Bethlehem Twp.- Nancy Run Fire
15 - Hanover Twp. Fire / EMS
16 - Lower Saucon Fire
17 - Bethlehem Twp. Fire / EMS
18 - Unassigned
19 - Unassigned
20 - Easton Fire / EMS
21 - Glendon - No Services
22 - Tatamy Fire
23 - West Easton Fire
24 - Wilson Fire
25 - Forks Twp. Fire
26 - Lower Mount Bethel Twp. Fire
27 - Palmer Twp. Fire / Suburban EMS
28 - Williams Twp. Fire
29 - Unassigned
30 - Bangor Fire (3 companies)
31 - East Bangor Fire
32 - Pen Argyl Fire
33 - Portland Fire
34 - Roseto Fire
35 - Wind Gap Fire / EMS
36 - Plainfield Twp. Fire / EMS
37 - Upper Mount Bethel Twp. Fire
38 - Washington Twp. Fire
39 - Upper Mount Bethel Twp.- North Bangor Fire
40 - Bath Fire
41 - Chapman - No Services
42 - Northampton Fire
43 - North Catasauqua Fire
44 - Walnutport Fire
45 - Allen Twp. Fire
46 - East Allen Twp. Fire / EMS
47 - Lehigh Twp. Fire
48 - Moore Twp. Fire / EMS
49 - Northampton Regional EMS
50 - Nazareth Fire / EMS
51 - Stockertown - No Services
52 - Bushkill Twp. Fire / EMS
53 - Lower Nazareth Twp. Fire
54 - Upper Nazareth Twp. Fire 

Non-ESN Based Station Numbers

63 - Lower Saucon Twp.- Steel City Fire
67 - Northern Valley EMS
71 - Blue Valley Rescue Squad
72 - Pennsylvania Water Rescue
80 - Lehigh University QRS
99 - Northampton County EMA (Uses Plain English for All Vehicles)

Third and Fourth Numbers = Unit Type and Individual Unit
11-19 - Engine (or XX Engine X)
21-29 - Ladder (or XX Ladder X)
31-39 - Tanker
41-49 - Rescue/Brush/Utility/Mini-Pumper (or XX Type X)
50-59 - Fire Officers
60 - Fire Marshall
61-69 - Miscellaneous Officers
70-79 - EMS Officers
81-89 - Ambulance
90-99 - Fire Police 

Also (Where XX = ESN)
XX ATV # - All-Terrain Vehicle
XX EMS # - Ambulance (used currently for Bethlehem City and Suburban EMS)
XX Medic # - Non-Transporting ALS Squad
XX QRV # - Non-Transporting BLS Squad