UPU S10 Check Digit Calculator

How UPU S10 Check Digit Calculator Works?

The UPU S10 Check Digit Calculator works by multiplying the 8 serial digits of a postal item identifier by weights 8, 6, 4, 2, 3, 5, 9, 7, subtracting the remainder modulo 11 from 11, and mapping 10 to 0 and 11 to 5.

1. 1Enter the 2-letter service indicator, 8-digit serial, and 2-letter country code.
2. 2Multiply the 8 digits by 8, 6, 4, 2, 3, 5, 9, and 7.
3. 3Add the products and compute 11 − (S mod 11).
4. 4Map 10 to 0 and 11 to 5.
5. 5Place the check digit after the serial: AA 12345678 C CC.

UPU S10 Check Digit Calculator Formula

The UPU S10 formula is C = 11 − (Σ dᵢ·wᵢ mod 11), with 10 → 0 and 11 → 5.

S = 8d₁ + 6d₂ + 4d₃ + 2d₄ + 3d₅ + 5d₆ + 9d₇ + 7d₈
C = 11 − (S mod 11);  10 → 0;  11 → 5

• d₁…d₈ are the serial digits.

S = 200
C = 11 − (200 mod 11) = 9
Item = AA473124829GB

UPU S10 Check Digit Calculator Conversion Table

The UPU S10 conversion table lists service indicators with sample identifiers.

What is UPU S10 Check Digit Calculator?

A UPU S10 Check Digit Calculator is a tool that computes the check digit of a 13-character international postal item identifier defined by the Universal Postal Union (UPU) standard S10.

Every tracked international letter, registered item, EMS item, and parcel carries an S10 identifier, so 192 postal operators can track the same item.

What are the uses of UPU S10 Check Digit Calculator?

There are 3 main uses of the UPU S10 Check Digit Calculator, including label printing, tracking lookups, and customs declarations.

• Label printing: Postal operators and shippers generate S10 barcodes.
• Tracking lookups: Tracking sites reject mistyped item numbers.
• Customs declarations: Shippers link CN22/CN23 forms to the item ID.