Guides
  1. E-Way Bill

Update Part-B (assign or change vehicle)

Use Part-B updates to:

  • Assign a vehicle for the first time after a Part-A-only generation (the EWB was created without a vehicle and the transporter is now naming one).
  • Change the vehicle mid-journey because of a breakdown, transhipment, or any other reason the goods are moving on a different lorry.

NIC permits unlimited Part-B updates while the EWB is active. Each update appends a new entry to the EWB's vehicle history — nothing is overwritten.

The call

POST /v1/ewaybills/partb HTTP/1.1
Host: api.in.onefinops.com
Authorization: Bearer eyJhbGciOi...
gstin: 29ABCDE1234F1Z5
Content-Type: application/json
X-Request-Id: 4f1d8a2c-…
{
  "ewbNumber": 112345678901,
  "vehicleNumber": "KA01AB9999",
  "vehicleType": "R",
  "transportMode": "1",
  "transportDocumentNumber": "LR-2026-7788",
  "transportDocumentDate": "2026-05-15",
  "fromPlace": "Bengaluru",
  "fromStateCode": "29",
  "reasonCode": "2",
  "reasonRemark": "Vehicle handover at Hosur"
}

reasonCode:

ValueReason
"1"Break down
"2"Transhipment
"3"Others
"4"First time (initial vehicle assignment after a Part-A-only generation)

reasonRemark is free text, max 100 characters. NIC stores it against the vehicle history entry.

For rail, air, or ship transport (transportMode 2 / 3 / 4), vehicleNumber is not applicable — supply transportDocumentNumber and transportDocumentDate (RR, AWB, BL number and date) instead.

Response

The full EWB record reflecting the new vehicle assignment. The earlier vehicle entries remain in the audit history.

What this doesn't change

  • Validity (validUpto). A Part-B update doesn't push validity out. If the journey is taking longer than NIC's default window, see Extend validity.
  • Transporter. Part-B updates the vehicle, not the entity carrying the consignment. To hand the EWB over to a different transporter, see Update transporter.

Where to next