šŸš— Official LTA Mod-19 Specification

Singapore Vehicle Plate Engine

Complete checksum validator, reverse missing character solver, bulk auditor, and realistic test data generator for Singapore registration numbers.

šŸ” Real-Time Checksum Verifier

Type any Singapore registration number to verify its modulus 19 checksum letter and inspect its exact vector dot-product calculation.

SBA 1234 G
Quick Samples:
āœ“ Valid Checksum

License plate passes Singapore Land Transport Authority Mod-19 verification.

šŸ·ļø Private Passenger Vehicle
šŸ”¤ Prefix: SBA (3 letters)
šŸ”¢ Number: 1234
Dot-Product Matrix & Modulo-19 Breakdown Weights: [9, 4, 5, 4, 3, 2]
Vector Element Prefix L1 Prefix L2 Digit 1 Digit 2 Digit 3 Digit 4
Raw Character B A 1 2 3 4
Numerical Value 2 1 1 2 3 4
Fixed Weight Ɨ 9 Ɨ 4 Ɨ 5 Ɨ 4 Ɨ 3 Ɨ 2
Product 18 4 5 8 9 8
Sum = 18 + 4 + 5 + 8 + 9 + 8 = 52
52 mod 19 = 14 ā†’ 'G'
šŸ§© Missing Character Reverse Deduction Engine

Have an incomplete license plate from a dashcam, witness statement, or faded plate? Enter wildcards (?, *, or _) in any position to mathematically solve for all possible valid registrations.

Solver Examples:
Found 1 mathematically valid plate:
šŸ“Š Bulk Plate Fleet Auditor

Paste raw license plate numbers or CSV records (one per line, comma/space separated) to audit entire vehicle fleets in parallel.

0
Total Scanned
0
Valid Plates
0
Invalid / Errors
0%
Pass Rate
# Input Plate Calculated Checksum Category Status
Paste plates above and click "Run Batch Audit" to review fleet records.
āš” Synthetic Test Plate Generator

Generate realistic Singapore vehicle plates with mathematically certified checksums for QA testing, database seeding, or mock datasets.

šŸ“ Algorithm Specification & Developer API

Complete mathematical breakdown of the Singapore Land Transport Authority (LTA) Modulo-19 registration checksum formula.

1. Prefix Letters to Number Conversion

Singapore plates have 1 to 3 prefix letters (e.g. SBA, PA, E):

  • 3 Prefix Letters (e.g. SBA): Discard the first letter (S is ignored). Use the 2nd and 3rd letters: B and A.
  • 2 Prefix Letters (e.g. PA, EV): Use both letters as \(L_1\) and \(L_2\).
  • 1 Prefix Letter (e.g. E, Q): Pad with a leading zero: \(L_1 = 0\), and \(L_2 =\) letter value.
  • Letters convert using 1-based alphabetical indexing: \(A = 1, B = 2, \dots, Z = 26\).

2. 4-Digit Numerical Vector

The numerical portion contains 1 to 4 digits. It is always left-padded with zeros to form exactly 4 digits \([D_1, D_2, D_3, D_4]\) (e.g. 1 becomes 0001, 28 becomes 0028).

3. Vector Weights & Modular Arithmetic

The 6-element vector is multiplied by fixed weight matrix \(W = [9, 4, 5, 4, 3, 2]\):

Sum = (Lā‚ Ɨ 9) + (Lā‚‚ Ɨ 4) + (Dā‚ Ɨ 5) + (Dā‚‚ Ɨ 4) + (Dā‚ƒ Ɨ 3) + (Dā‚„ Ɨ 2)

Compute remainder \(R = \text{Sum} \pmod{19}\). The resulting remainder is mapped to the checksum alphabet:

0ā†’A, 1ā†’Z, 2ā†’Y, 3ā†’X, 4ā†’U, 5ā†’T, 6ā†’S, 7ā†’R, 8ā†’P, 9ā†’M, 10ā†’L, 11ā†’K, 12ā†’J, 13ā†’H, 14ā†’G, 15ā†’E, 16ā†’D, 17ā†’C, 18ā†’B

Note: Checksum letters F, I, N, O, Q, V, W are omitted by LTA to prevent visual confusion on road enforcement cameras.

Copied to clipboard!