E-Way Bill Validity: Distance-Based Formula, Part B Update and Extension Rules

An e-way bill is valid for 1 day per 200 km (or part thereof) for regular cargo, and 1 day per 20 km for over-dimensional or multimodal cargo, under Rule 138(10) of the CGST Rules 2017. A 450 km journey therefore gets 3 days of validity. The validity clock starts at generation; Part B (transporter and vehicle details) must be updated before movement begins; and the validity can be extended by the transporter or consignor within 8 hours before or after expiry.

What the law actually requires

Rule 138 of the CGST Rules 2017 governs e-way bills. Sub-rule (10) fixes validity by distance, and sub-rule (10)(iii) allows extension. Getting the arithmetic wrong means the goods travel on an expired document — which the check-post system flags as a vehicle moving without a valid e-way bill, attracting the Section 129/130 enforcement machinery.

The distance formula

Part thereof is the phrase that matters. The validity is rounded up to the next full day, not down. 201 km is 2 days, not 1. The standard examples:

When the clock starts

Validity is counted from the time of generation, and the day of generation counts as Day 1. An e-way bill generated at 2:00 p.m. on 3 August for a 450 km journey is valid through 11:59 p.m. on 5 August (Day 1 = 3 Aug, Day 2 = 4 Aug, Day 3 = 5 Aug). Teams that think "3 days from 3 August" means "expires 6 August" are carrying a bill that lapses a day before they expect it to.

Part B: update it before the truck moves

An e-way bill has two parts. Part A carries the consignor, consignee, invoice and goods details. Part B carries the transporter and vehicle (transport document number, vehicle number). The generator can create Part A and update Part B later — but the vehicle must not move until Part B is updated. A bill that moves with a blank Part B is invalid for transit; the enforcement systems treat it as no e-way bill at all. In practice: generate Part A at dispatch, enter the vehicle number in Part B at the loading bay, and only then release the truck.

Worked example: Aakash Logistics moves 850 km

Aakash Logistics Pvt Ltd ships a consignment of packaging machinery from Delhi to Mumbai — 1,420 km by road. Under the regular-cargo formula: 1,420 ÷ 200 = 7.1 → 8 days validity.

The journey finishes on 7 August, comfortably within the 8-day window. Now suppose the truck is delayed in transit and will not reach Mumbai until 11 August — one day past expiry. The transporter must apply for an extension under Rule 138(10)(iii), and it can be done within 8 hours before expiry or 8 hours after expiry (extensions are permitted up to 8 hours before the expiry time and up to 8 hours after the expiry time). An extension request filed on 11 August, after the 8-hour post-expiry window has passed, is rejected — and the only remedy is a fresh e-way bill for the remaining leg, which in practice requires a fresh document or a revised Part-A entry.

What a director should actually watch

• Compute validity from the time of generation, counting the generation day as Day 1. Use ceil(distance ÷ 200) — round up, never down.
• Treat Part B as the release gate. No vehicle number in Part B, no movement. A blank Part B is an invalid e-way bill.
• Calendar the 8-hour extension window. Extensions are only accepted within 8 hours before or after expiry. After that, the bill is dead and a fresh document is needed.
• Match the cargo class. Over-dimensional or multimodal cargo gets 1 day per 20 km — a formula that is easy to misapply to an ordinary heavy truck. Confirm the classification before generating.
• Watch Part A vs GSTR-1 consistency. The distance/validity data and the invoice value in Part A should reconcile with your e-invoice and GSTR-1, since the e-way bill system and e-invoice system are linked for covered taxpayers.

Changed FY 2025-26: For e-invoice-covered taxpayers, e-way bill Part A generation via the invoice route now requires a valid IRN for the invoice being transported. No IRN, no Part-A generation through the invoice path — goods movement stalls before it starts. Confirm the current integration behaviour on the portal.

FAQ

How long is an e-way bill valid?
One day per 200 km (or part thereof) for regular cargo; one day per 20 km for over-dimensional or multimodal cargo. 450 km = 3 days; 1,020 km = 6 days.

Does the day of generation count?
Yes. Validity runs from the time of generation and the generation day is Day 1. A bill generated at 2 p.m. on 3 August for a 450 km trip expires 11:59 p.m. on 5 August.

Can I update Part B after generating Part A?
Yes — but the vehicle must not move until Part B is updated. A bill moving with blank Part B is invalid for transit.

Can an e-way bill be extended?
Yes, under Rule 138(10)(iii), by the transporter or consignor within 8 hours before or after expiry. After that window, the bill cannot be extended.

What if the e-way bill expires mid-journey?
Stop the vehicle, apply for extension within the 8-hour window, or generate a fresh e-way bill for the remaining leg. Moving on an expired bill exposes the goods to Section 129 action (tax and penalty payable to release the goods).

Is the validity different for over-dimensional cargo?
Yes — 1 day per 20 km instead of 1 day per 200 km. Confirm the cargo classification before generating.

Generate and validate e-way bills for your consignments: /tools/e-way-bill-generator. For a GST compliance audit of your company, visit pvtltd.co.

Sources

• Rule 138(10) and Rule 138(10)(iii), CGST Rules 2017
• Section 129 CGST Act 2017 (detention, seizure and release of goods)
• E-way bill portal / GSTN guidance on Part A, Part B and extension windows

-: current extension-window guidance and IRN-linked Part A behaviour for covered taxpayers

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See Also

• E-Way Bill Exemption: Intra-State Below ₹50K, Exempted Goods and State-Specific Rules
• E-Invoice Auto-Populates GSTR-1: What Flows, What Still Needs Manual Entry
• IRN Generation: ICP API, JSON Schema and Common Errors on the E-Invoice Portal