Your truck is loaded, the invoice is correct, and the e way bill looks fine on screen. Then it gets stopped at a check post not for tax evasion, not for missing paperwork, but because the validity had already run out an hour earlier.
The reason usually traces back to one small field: pin to pin distance in GST. It looks like a minor technical detail, the kind of thing you fill in and move past. It is actually the number that decides how many days your shipment is legally allowed to stay on the road.
Most e way bill problems are not complicated once you trace them back. They start with a PIN code typed in a hurry, without checking whether it matched where the goods were really leaving from.
Get that road distance wrong, and one of two things happens. Either the e way bill expires before delivery, or the declared route does not match what the vehicle is actually doing. Both get flagged at a check post. This guide covers how the GST portal calculates this distance, what to do when it returns an error code instead of a kilometre figure, and where the real, avoidable mismatches come from.
How Does the PIN Code Decide E Way Bill Validity?
Every PIN code in India maps to a known location. India Post built the system decades ago purely to route mail efficiently.
The e way bill portal borrowed that same six digit structure and pairs it with a distance database maintained by NIC, the National Informatics Centre. Enter a source and destination PIN, and the system is not drawing a straight line on a map, it is pulling an approved road distance from that stored database.
This figure does one specific job: it sets how long the e way bill stays valid. Nothing else on the form depends on it, but the entire transit timeline flows from this one number.
It also is not always instant. Some PIN pairs especially in newer localities or smaller towns with little freight movement simply do not have a distance stored yet. When that happens, the portal does not estimate anything. It asks you to enter the distance by hand, based on a reasonable route estimate rather than a rounded guess.
Where to Check the Distance Before Generating an E Way Bill?
You do not need to wait until the e way bill form is half filled to check pin to pin distance in GST. The portal has a standalone search tool for exactly this, which is useful for planning dispatch a day or two ahead.
Here is the process:
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Log into the e way bill portal at ewaybillgst.gov.in
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Open the Search menu and select Pin to Pin Distance
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Enter the source PIN and the delivery PIN
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Click Get Distance to see the approved kilometre figure
The same calculation runs quietly in the background later, when the e way bill is actually generated using the PIN codes in Part A. Checking it early just removes the guesswork before dispatch.
One thing worth knowing: a plain Google search for pin to pin distance usually surfaces a generic travel or mileage calculator. That is not the number tax officers go by. For compliance, only the figure from the official e way bill portal counts.
How Many Days of Validity Does Distance Actually Give?
For regular cargo, the rule allows one day of validity for every 200 km, or any part of that block. Over Dimensional Cargo works on a tighter band one day for every 20 km.
|
Distance (Pin to Pin) |
Validity (Regular Cargo) |
|
Up to 200 km |
1 day |
|
201 to 400 km |
2 days |
|
401 to 600 km |
3 days |
|
601 to 800 km |
4 days |
|
801 to 1,000 km |
5 days |
|
Every extra 200 km |
+1 day |
A 450 km shipment gets 3 days, not 2, since the leftover 50 km still counts as a full block.
What catches people out more often is when the clock actually starts. It begins the moment the e way bill is generated, not when the truck leaves the warehouse. Generate it a day early to be safe, and you have already burned into your transit window before the vehicle has moved at all.
What Do E Way Bill Distance Errors Like 702, 709 or 710 Actually Mean?
This part rarely gets covered properly, and it is usually where dispatch teams working through ERP or billing software actually get stuck. A handful of error codes show up repeatedly:
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Error 702 distance too high: The entered figure is well beyond what is expected for that PIN pair. Usually the wrong delivery PIN got picked, or someone entered the full multi leg route instead of just the current leg.
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Error 709 distance not available: The database has no stored distance for this PIN pair. Manual entry is needed, based on an actual route estimate.
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Error 710 invalid state code for the PIN: The PIN and the selected state do not match. Common when a state is picked from memory instead of being checked against the actual PIN.
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Error 721 distance not available, please provide distance: Similar to 709 the portal needs a manually entered number, ideally one you can explain later if asked.
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Error 820 document older than 180 days: The invoice or challan behind the e way bill is too old to generate against.
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Error 821 extension not allowed, 360 day cap reached: E way bills can only be extended up to 360 days from the original generation.
If your team runs high dispatch volumes, keep this list somewhere the warehouse or billing staff can check quickly. These errors tend to repeat for the same customers or warehouses if the underlying address data is not fixed at the source.
Why Do Shipments Still Get Detained Even With a Correct E Way Bill?
Most pin to pin distance in GST disputes trace back to a small set of repeat habits, rarely anything intentional.
The most common one: using the billing address PIN instead of the actual dispatch location. A business might be registered in one city but shipping from a warehouse in another. Use the registered office PIN, and the whole validity window gets calculated for a journey that never actually happened.
A shipment can look completely fine on paper, correct invoice, correct HSN, correct tax amount and still fail purely because of this one field. That is what makes it easy to overlook during routine checks.
The second is multi hub movement. When goods move from a factory to a regional warehouse, and separately from there to the customer, each leg needs its own e way bill and its own PIN pair.
A frequent mistake: entering the final customer PIN as the destination on the first leg, even though the truck is only going as far as the warehouse. This inflates the distance, hands over more validity than needed, and creates a mismatch an officer can flag immediately because the route on record will not match what the vehicle is actually doing.
For single haul routes beyond roughly 3,000 km, the system expects the movement split into staged e way bills instead of one continuous document. This shows up constantly with online sellers dispatching from multiple fulfilment centres.
There is also the 10% tolerance rule, which gets misunderstood as often as it gets ignored:
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A manual entry can go up to 10% above the system figure, for genuine route variations like a closed highway or a hill detour
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It cannot go lower because that would artificially shrink a validity window that should be longer
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If the real route is more than 10% longer, split the journey into separate e way bills instead of forcing a bigger override
Does an E Invoice Affect the Distance on an E Way Bill?
These two get mixed up often enough to separate clearly. The e invoice system generates the Invoice Reference Number and QR code purely from invoice data. Distance has nothing to do with that process.
The actual calculation happens only inside the e way bill workflow, using the PIN codes entered in Part A.
Where they connect is when an e invoice feeds into an e way bill which is the standard flow for B2B transactions above the e invoicing threshold. The Ship to address and GSTIN carry straight over into the e way bill dispatch details.
So if the invoice has an incorrect billing PIN, or the ERP auto fills the registered office instead of the real warehouse, that error quietly becomes a distance problem downstream, usually discovered only after the e way bill is already generated.
If you run ERP integrated invoicing, it is worth a one time check on whether the dispatch field is genuinely mapped to warehouse records, not the company registered address. These two are more often different than teams expect.
Who is Responsible If the Distance on the E Way Bill Turns Out Wrong?
This rarely gets spelled out clearly, and it causes confusion during audits. The distance figure is entered by whoever generates the e way bill, usually the supplier or consignor, unless the transporter has specific access to Part B.
That means responsibility for a wrong PIN, and the wrong distance that follows, sits with whoever generated the document. Not the driver.
This matters because a transporter often cannot fix a wrong PIN once the truck is already on the road. If the mistake happened back at the warehouse, the fix has to happen at the source. Cancel and regenerate within the permitted window, or request an extension using the correct remaining distance if the shipment is already moving.
Enforcement also is not uniform. Some states run tighter checks at border check posts and toll integration points than others, particularly for high value goods. A mismatch that goes unnoticed on a short local hop is far more likely to get flagged once the route crosses a state line.
Does This Matter More When Generating Hundreds of E Way Bills a Month?
For a business generating five e way bills a month, one wrong PIN is an occasional headache. For one generating five hundred, the same mistake repeated across similar shipments becomes a pattern and patterns get noticed faster during audits than one off errors.
Businesses using ERP or billing software to auto generate e way bills should treat their address master data as the actual source of truth, not the e way bill form itself. If the warehouse PIN is wrong in the customer or location master, every shipment built from that record inherits the same distance error.
It is worth running a periodic check: pull a sample of recent e way bills and compare the declared PIN pair against where goods actually moved. A pattern of errors tied to one warehouse or one customer account usually points to a master data fix, not individual corrections.
What to Check Before Generating the Next E Way Bill?
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Confirm the starting PIN reflects where goods are physically leaving from, not the registered office
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Confirm the delivery PIN matches the actual drop off point for this leg, not the final customer if it is an intermediate hop
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If the distance shown looks unusually high or low, check whether the wrong PIN was picked before overriding anything manually
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Generate the e way bill only when the vehicle is genuinely ready to move, not a day in advance
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When extending validity mid route, enter the remaining distance from the current location, not the original full route figure
Frequently Asked Questions
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What is pin to pin distance in GST?
It is the road distance the e way bill portal calculates between a shipment source and destination PIN codes, using its NIC backed database. This figure sets how many days the e way bill stays valid.
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How do I check pin to pin distance for an e way bill?
Log in to the e way bill portal, go to Search, select Pin to Pin Distance, and enter the source and delivery PIN codes. The tool returns the distance in kilometres.
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Why does my e way bill show a distance error?
Usually it is error 702 (too high), 709 or 721 (not available for that PIN pair), or 710 (PIN does not match the selected state). Each points to a different cause, check the exact message before changing anything.
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Can I enter a lower distance to shorten validity?
No. A manual entry can go up to 10% above the system figure for genuine route variations, but a lower distance is not permitted.
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What happens if my e way bill expires mid transit?
It is treated as non compliant even if the goods are genuinely still moving, and this can lead to detention. Extensions need to be requested before expiry, using the remaining distance from the current location.
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Does this apply to e invoices too?
Not directly. The e invoice system, connected to gst.gov.in data standards, generates the IRN and QR code from invoice data alone. But since Ship to details from an e invoice feed into the e way bill Part A, a wrong dispatch address on the invoice can throw off the distance calculated later.
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What is the difference between the portal distance and the actual route a driver takes?
The portal figure is an approved estimate from a stored database, not a live GPS route. Actual driven distance can vary because of road closures or diversions which is exactly what the 10% tolerance allowance is meant to absorb.
Conclusion
None of this needs much beyond attention to one field. Pin to pin distance in GST is calculated automatically once the PIN codes are entered. What actually needs checking is whether those PIN codes reflect where goods are genuinely moving from and to, not what the saved master data happens to default to.
A short check at dispatch catches nearly all of this before it turns into a conversation at a check post. If the same errors keep showing up across shipments, that is usually a sign the underlying address records need cleaning up, not that each e way bill needs fixing one at a time.
If you want a team to handle your compliance seamlessly without tracking manual errors, you can explore specialized support channels like gstfilling.co to automate tracking workflows.
About Author:
Ankit Prajapat is an SEO Executive and Compliance Content Strategist with hands on experience at LegalDev Tax India Pvt. Ltd. Working closely with CA and CS professionals, Ankit specializes in simplifying complex GST, taxation, and corporate compliance topics into actionable, easy to understand guides for Indian businesses.