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Dingoo Barcode Format

Barcodes (order IDs) generated by the invoice flow follow an 18-character format. They serve both as a unique shipment identifier and as a scannable barcode on the physical label.

Structure

[country(2)] [zone(4)] [size(1)] [serial(8)] [volume(2)] [checkdigit(1)]
Field Length Description
country 2 chars ISO country code (e.g. PT)
zone 4 digits Distribution zone code (zero-padded)
size 1 digit Package size code (1–5, or 0 if unknown)
serial 8 digits Sequential number fetched from MongoDB (zero-padded)
volume 2 digits Parcel index within the invoice (1 to 99, zero-padded)
checkdigit 1 digit Integrity check digit

Example: PT9876100000123018

PT   9876   1   00000123   01   8
↑     ↑     ↑      ↑        ↑   ↑
country zone size serial  vol  cd
  • country = PT
  • zone = 9876
  • size = 1
  • serial = 00000123
  • volume = 01 (first parcel of the invoice)
  • check digit = 8

Barcode Generation per Invoice

When an invoice with N parcels is imported:

  1. A unique serial is fetched from MongoDB for each parcel (via an atomic counter).
  2. The volume number is assigned sequentially: parcel 1 gets 01, parcel 2 gets 02, etc.
  3. The size code comes from the size field of each InvoiceOrderItem (1–5).
  4. The check digit is computed from the 15 numeric characters that make up the barcode body.

Check Digit Algorithm

The check digit protects against transcription errors. It is computed from the 15 numeric characters that sit between the 2-char country code and the check digit itself.

P  T  9  8  7  6  1  0  0  0  0  0  1  2  3  0  1  ?
└──┘  └─────────────────────────────────────────┘  └┘
 country       numeric part (15 digits)             cd

The numeric part is the direct concatenation of the four inner fields:

numeric_part = zone(4) + size(1) + serial(8) + volume(2)
             = "9876"  +  "1"  + "00000123" +  "01"
             = "987610000012301"    (15 digits)

Steps

  1. Reverse the 15-digit numeric part.
  2. For each digit at position i (starting at 0), assign weight 3 if i is even, 1 if i is odd.
  3. Sum all digit × weight products.
  4. Check digit = (10 − (sum mod 10)) mod 10.

Worked Example — PT9876100000123018

Numeric part: 987610000012301

Reversed: 103210000016789

i Digit Weight Product
0 1 3 3
1 0 1 0
2 3 3 9
3 2 1 2
4 1 3 3
5 0 1 0
6 0 3 0
7 0 1 0
8 0 3 0
9 0 1 0
10 1 3 3
11 6 1 6
12 7 3 21
13 8 1 8
14 9 3 27

Sum = 3 + 9 + 2 + 3 + 3 + 6 + 21 + 8 + 27 = 82

Check digit = (10 − (82 mod 10)) mod 10 = (10 − 2) mod 10 = 8 ✓

The last character of PT9876100000123018 is indeed 8.

Python Reference

def _check_digit(numeric_part: str) -> int:
    digits = list(map(int, numeric_part[::-1]))
    total = sum(d * (3 if i % 2 == 0 else 1) for i, d in enumerate(digits))
    return (10 - (total % 10)) % 10

Size Codes

Code Description
1 Extra Small
2 Small
3 Medium
4 Large
5 Extra Large