S10 Validation Tool

Hey! This is a validator for the Universal Postal Union's S10 standard of international mail identification. It's a 13-character code that identifies type and origin country for international mail.

You can validate a code of your own by inserting it into the box below. Alternatively, you can use "RR301591815EE" as a valid example code, or "AA123456789ZZ" as an invalid one.

Service
Indicator

Serial
Number

Check
Digit

Country
Code

Service indicator

The service indicator is a two-letter code indicating what the package is. For this specific S10 identifier, the service indicator is , meaning:
.

	A	B	D	E	N	V
A	Unassigned					D/BMA
B	Domestic items; items subject to bilateral and/or multilateral agreements
C	Parcel post
D	Domestic items; items subject to bilateral and/or multilateral agreements
E	Express Mail Service
F	Unassigned
G	D/A	Unass.	D/A	Unassigned
H	E-commerce parcels
I	Unassigned
J	Reserved
K	Reserved
L	Letter post (tracked)
M	M bags
N	Domestic items; items subject to bilateral and/or multilateral agreements
O	Unassigned
P	Domestic items; items subject to bilateral and/or multilateral agreements
Q	International Business Reply Service				Unassigned
R	Letter post (registered)
S	Reserved
T	Reserved
U	Letter post (generic)
V	Letter post (insured)
W	Reserved
X	Unassigned
Y	Unassigned
Z	Domestic items; items subject to bilateral and/or multilateral agreements

Unassigned / reserved
Express Mail Service
Letter post
Parcel post
Domestic/bilateral/multilateral use only

Check digit

The check digit is calculated from the previous 8 digits in the serial number. It's a quick way to check if the S10 identifier is valid.

		× 8
		× 6
		× 4
		× 2
		× 3
		× 5
		× 9
+		× 7
200

11 − ( mod 11) =

11 − () =

< 10?
→ Check digit is .

= 10?
→ Check digit is 0.

→ Check digit is 5.

Country code

Country codes are two-letter codes from the ISO 3166-1 alpha-2 standard. For this specific S10 identifier, the country code is , which is .