USPS Service/Class IDs

USPS responses will contain a Class ID or Service ID depending on if you are requesting domestic or international rates. Class IDs are returned for domestic rates. The service_code parameter in the getSimpleRates() function will map to one of these values. See: Using Simple Rates

Class IDs

____ in the chart denotes a variable depending on the scheduled delivery date calculation between the origin and destination ZIP Codes.

Possible values:

  • 1-Day
  • 2-Day
  • 3-Day
  • Military
  • DPO
Value Description
0 First-Class Mail Large Envelope
0 First-Class Mail Letter
0 First-Class Mail Parcel
0 First-Class Mail Postcards
1 Priority Mail ____
2 Priority Mail Express ____ Hold For Pickup
3 Priority Mail Express ____
4 Standard Post
6 Media Mail
7 Library Mail
13 Priority Mail Express ____ Flat Rate Envelope
15 First-Class Mail Large Postcards
16 Priority Mail ____ Flat Rate Envelope
17 Priority Mail ____ Medium Flat Rate Box
22 Priority Mail ____ Large Flat Rate Box
23 Priority Mail Express ____ Sunday/Holiday Delivery
25 Priority Mail Express ____ Sunday/Holiday Delivery Flat Rate Envelope
27 Priority Mail Express ____ Flat Rate Envelope Hold For Pickup
28 Priority Mail ____ Small Flat Rate Box
29 Priority Mail ____ Padded Flat Rate Envelope
30 Priority Mail Express ____ Legal Flat Rate Envelope
31 Priority Mail Express ____ Legal Flat Rate Envelope Hold For Pickup
32 Priority Mail Express ____ Sunday/Holiday Delivery Legal Flat Rate Envelope
33 Priority Mail ____ Hold For Pickup
34 Priority Mail ____ Large Flat Rate Box Hold For Pickup
35 Priority Mail ____ Medium Flat Rate Box Hold For Pickup
36 Priority Mail ____ Small Flat Rate Box Hold For Pickup
37 Priority Mail ____ Flat Rate Envelope Hold For Pickup
38 Priority Mail ____ Gift Card Flat Rate Envelope
39 Priority Mail ____ Gift Card Flat Rate Envelope Hold For Pickup
40 Priority Mail ____ Window Flat Rate Envelope
41 Priority Mail ____ Window Flat Rate Envelope Hold For Pickup
42 Priority Mail ____ Small Flat Rate Envelope
43 Priority Mail ____ Small Flat Rate Envelope Hold For Pickup
44 Priority Mail ____ Legal Flat Rate Envelope
45 Priority Mail ____ Legal Flat Rate Envelope Hold For Pickup
46 Priority Mail ____ Padded Flat Rate Envelope Hold For Pickup
47 Priority Mail ____ Regional Rate Box A
48 Priority Mail ____ Regional Rate Box A Hold For Pickup
49 Priority Mail ____ Regional Rate Box B
50 Priority Mail ____ Regional Rate Box B Hold For Pickup
53 First-Class/ Package Service Hold For Pickup
55 Priority Mail Express ____ Flat Rate Boxes
56 Priority Mail Express ____ Flat Rate Boxes Hold For Pickup
57 Priority Mail Express ____ Sunday/Holiday Delivery Flat Rate Boxes
58 Priority Mail ____ Regional Rate Box C
59 Priority Mail ____ Regional Rate Box C Hold For Pickup
61 First-Class/ Package Service
62 Priority Mail Express ____ Padded Flat Rate Envelope
63 Priority Mail Express ____ Padded Flat Rate Envelope Hold For Pickup
64 Priority Mail Express ____ Sunday/Holiday Delivery Padded Flat Rate Envelope

Service IDs (International Rating)

Value Description
1 Priority Mail Express International
2 Priority Mail International
4 Global Express Guaranteed (GXG)
5 Global Express Guaranteed Document
6 Global Express Guaranteed Non-Document Rectangular
7 Global Express Guaranteed Non-Document Non-Rectangular
8 Priority Mail International Flat Rate Envelope
9 Priority Mail International Medium Flat Rate Box
10 Priority Mail Express International Flat Rate Envelope
11 Priority Mail International Large Flat Rate Box
12 USPS GXG Envelopes
13 First-Class Mail International Letter
14 First-Class Mail International Large Envelope
15 First-Class Package International Service
16 Priority Mail International Small Flat Rate Box
17 Priority Mail Express International Legal Flat Rate Envelope
18 Priority Mail International Gift Card Flat Rate Envelope
19 Priority Mail International Window Flat Rate Envelope
20 Priority Mail International Small Flat Rate Envelope
21 First-Class Mail International Postcard
22 Priority Mail International Legal Flat Rate Envelope
23 Priority Mail International Padded Flat Rate Envelope
24 Priority Mail International DVD Flat Rate priced box
25 Priority Mail International Large Video Flat Rate priced box
26 Priority Mail Express International Flat Rate Boxes
27 Priority Mail Express International Padded Flat Rate Envelope