Check your CSN against the line’s SAM first

Your CSN and the shipping line's SAM (SDM for an export) are two filings on the same master BL, and customs matches them. When they do not match, somebody pays — usually the forwarder, through an IGM amendment the line files and charges for. This page explains when a mismatch is still free to fix, how SCMTR checks your CSN against the line's SAM before it goes to ICEGATE, and how a shipping line can share its SAM so every CSN holder finds out before the line files.

What does an IGM amendment cost a forwarder?

An IGM amendment is the line's SAA (SDA for an export). A forwarder cannot file it: customs takes an amendment request only from the carrier or its agent, so the line files it and bills whoever asked.

The line's charge. Lines now charge up to ₹10,000 per amendment request, and more than one raised its charge in 2026.Customs' fee. ₹1,000 for amending an import or export manifest (the published fee, not yet reworded for SCMTR's messages).The wait. While the amendment is pending, the Bill of Entry cannot be filed — ICEGATE refuses it with 635 ("BL/HBL not available in IGM") — and no demurrage or detention waiver covers the time spent waiting. The trade has reported 10–15 days for a short-landing amendment's approval; customs' own target is 24 hours.

When is a mismatch still free to fix?

Before the line files its SAM, every correction is free. A CSN amended before the SAM is simply picked up when the line files it, and since ICES Advisory 38/2026 a CSN can even be deleted and filed again while no SAM refers to it. After the SAM, the same correction is an SAA — the line's charge, customs' fee and a held Bill of Entry.

So the whole job is to find every disagreement before the line files. In practice the line usually files a day or more after the forwarder's CSN, and one to three days before entry inwards; one large carrier asks for the CSN by ETA − 72 hours and takes amendment requests up to ETA − 8 hours.

When is my CSN due, and will SCMTR remind me?

The deadline that matters is the line's cut-off for CSNs — after it the line files its SAM with what it has.

If the line has shared its SAM on SCMTR, it sets its own cut-off, and you see it: on the Sign & upload check, on the line's link, and in every reminder ("The line asks for CSNs by …").If it has not, SCMTR uses the cut-off your line published for the call on the CSN cut-off board (scmtr.io/cutoffs). When your CSN names its line (its master bill's letters, or its boxes' container agent), only that line's cut-off is used — never another line's on the same ship; when it names none, the reminder says which line's cut-off it is.If the board has none, it uses the rule your CSN's line publishes for India when that rule counts from the arrival (Maersk's and CMA CGM's, 72 hours before), worked out from the arrival customs lists for your VCN and marked estimated. Where the line publishes no such rule, it counts 72 hours back from that arrival and says that this is a common cut-off, not your line's word. Your line may ask earlier.Every cut-off here is indicative: the line's own advisory is the only authority, so confirm it with the line.A CSN you have started and not sent is reminded to you a day before the cut-off, and once more if it passes while the ship is still out. After the cut-off the line may already have filed — Sign & upload then tells you first whether it carried your BL straight.If the line named you on a BL and customs does not hold your CSN on it yet, you are reminded a day before the line's cut-off even if you have not started one.

You can turn these e-mails and phone notifications on or off in Settings → Alerts ("CSN due before the line's cut-off").

Why does a line end up amending its SAM for a forwarder?

What does SCMTR check when I press Sign & upload?

Before your token is asked for, SCMTR asks customs' own record what the line has filed for every master BL on your CSN, and compares it with your CSN field by field, using the same Fix / Check / OK to differ groups as what the line and the forwarder must match.

The Fix fields are the ones customs has refused filings for:

The container size is not on this list for you: ICES Advisory 38/2026 says customs checks it on the line's manifest only, and the one refusal for it (398, October 2026) fell on the line's SAA — where the CSN's size matched both bills of lading. A size that differs is still worth a look: check the box, and if yours is right, the line amends.

The seal and the shipper-owned flag are compared only against a line's shared copy: customs' public record carries neither, so against a filed SAM they are not checked. A different seal is a Check, never a Fix.

Why the MBL PDF. The line manifests what its own bill of lading says, so a CSN that differs from the MBL is likely to differ from the SAM too. It is the one check that works before the line has filed or shared anything.

Why a reason and not a hard stop. Your CSN may be the one that is right and the line's the one that must change. SCMTR never decides which; it makes sure nobody sends past a known refusal by accident. A check that cannot reach ICEGATE never holds a send back.

Why the BL date is compared and not used to look the BL up. ICEGATE's record finds a BL by its number at a port, and gives back the date the line used. A date that differs is exactly the refusal 164, so SCMTR asks for the line's dates first and shows the difference, rather than finding nothing and saying "not filed".

Will my amendment (SCA) make the line file an SAA?

Once the line's SAM is filed, the amendment screen sorts every change you made by whether the SAM carries it. For a line that quotes your CSN, customs' own trade-scenario table says what the SAM holds for each house BL — its number and date, its PCIN, its customs location and its containers — and what it leaves to your CSN.

A change that brings your CSN to what the line's SAM already holds needs no SAA: the SAM was right.

"No SAA" for parties, addresses, goods and HS codes is our reading of customs' table; no amendment of that kind has yet been seen through after a SAM without one. Treat it as the likely answer, not a promise.

What happens when the line shares its SAM on SCMTR?

A shipping line can put its SAM or SDM on SCMTR — usually the draft, before filing it — and share it with every forwarder who holds a CSN on it.

If you are on SCMTR, you are told in the bell and by e-mail, per BL: "matches your CSN", "differs from your CSN on packages", or "does not quote your CSN" (the line is about to carry your BL straight). The same answer appears when you press Sign & upload on a CSN for that BL, while the SAM is not yet filed.If you are not on SCMTR, the line sends you a link. Drop your CSN JSON on it and you see how each of your BLs reads against the line's copy. Your CSN is compared and not kept.A draft never stops your upload. It is the line's intention, not customs' record; only a SAM customs has accepted can hold a send back.

Who can see a line of a shared SAM?

A shared SAM holds every forwarder's BL on the vessel, so nobody sees the whole of it. A forwarder sees one line — its own BL — and only when one of these is true:

Customs' record lists your CSN on that BL.The line names your PAN as the consolidator on that line.Your PAN is the line's consignee or notify party on it.The line named you on that BL on SCMTR, or sent you its link.

The line is found by port and MBL number. What you see of it is the master BL's own details — date, packages, weight, containers, ports, what it quotes — the same things printed on the MBL you already hold. Why PAN alone is not enough: on a line the shipping line means to carry itself, the consolidator PAN is the line's own, so a PAN-only rule would hide exactly the BL that is about to be filed straight. Having your CSN on customs' record opens it — one more reason to file early.

Where do I see the SAMs lines have shared with me?

On CSN filing, a note appears when a line has shared a SAM with a BL of yours on it; it opens Lines that shared their SAM with you. Each shows only your own BLs: against your CSN where you have one on SCMTR (filed, or the draft you are writing), and otherwise the line's own details for the BL — the date, packages, weight, containers with seals, and what it quotes — so you can start your CSN from the same facts.

For shipping lines: how do I share my SAM before filing it?

Open the SAM or SDM in Shipping line filing and press Share with CSN holders. Tick "This is the SAM I filed" only if it is. For a draft, set Ask CSN holders to file by — your cut-off. It starts at 72 hours before the arrival your SAM states; change it to your own.

SCMTR asks customs, BL by BL, who holds a CSN on it, compares each CSN with your line, and tells every holder on SCMTR.Your board lists every line: the CSN holders customs shows on its BL, whether each matches, and whether they were told — or are not on SCMTR and should get your link. You see holders' PANs on your own BLs, as your own ICEGATE login already shows them.Your link can go to anyone by WhatsApp or e-mail; each person sees only the BLs their own CSN names.Name the forwarder on a BL by PAN on your board — one at a time, or paste "MBL PAN" pairs from your own sheet. A named forwarder on SCMTR is told at once and sees that BL against its own CSN; one not on SCMTR needs the link.Tick "A forwarder files a CSN for this BL" on any line you expect a CSN for. Lines that quote a CSN, and lines you named a forwarder on, are ticked for you.At your cut-off SCMTR reads your lines against customs' record again, tells forwarders whose position changed, and tells you which ticked lines still have no CSN — file those as they stand and each is refused, or becomes a paid SAA when the CSN arrives.Sharing a newer draft withdraws the old one, and a link can be withdrawn at any time. A share lasts 30 days.

Every mismatch found this way is one you fix before filing — no split to prepare, no SAA to file, no forwarder waiting on a Bill of Entry.

What can this not do?

A line that neither shares nor has filed leaves only your master BL to compare with — keep its PDF on file, and send the line your CSN details.Guess that a straight BL is really a consolidation. Only the line knows; that is why it can tick the line or name you on it.A CSN that cannot be filed in time is still late: SCMTR can make the deadline loud, not move the ship.Cargo that genuinely changes — short-shipped, split — still needs an amendment.Customs decides. A matching pair has never been seen refused on the four Fix fields, and that is all anyone can say.