How postal tracking numbers are built
India Post and almost every national post office use the same 13-character format, defined by the Universal Postal Union in standard S10:
EE 12345678 9 IN
│ │ │ └ country of posting (ISO code)
│ │ └ check digit
│ └ 8-digit serial number
└ service code (two letters)
The first letter shows the service. In India: E is Speed Post / EMS, C is international parcel, R is registered letter and L is often used for letter-post with tracking. Other letters are used for domestic products and vary over time.
The check digit
The 9th digit is calculated from the eight before it, so a single mistyped digit almost always produces an invalid number:
Multiply the 8 digits by 8, 6, 4, 2, 3, 5, 9, 7 and add them up.
Check = 11 − (sum mod 11). If that is 10 → 0. If it is 11 → 5.
This is why a “tracking number not found” error is often a typing mistake rather than a lost parcel: run it through the checker first.
Private couriers
Couriers such as Blue Dart, Delhivery, DTDC and Ekart use their own number formats without a public check digit, so they can only be checked on the courier’s own site. Use the official links below.
Questions people ask
My number is valid but tracking shows nothing. Why?
Can I track an international parcel posted to India?
Does a valid check digit mean the parcel exists?
Sources
Results are estimates to help you plan. Always confirm important numbers with the seller, carrier or authority concerned. Last reviewed: November 2026.