Shipper's Letter of Instruction: Fill It From the Order With AI

A shipper's letter of instruction (SLI) tells your freight forwarder what is moving, who ships and receives it, how it should travel and what paperwork to prepare. Yes, AI can fill most fields from order data, but the forwarder must check the result, and tariff codes, values and party details need a person to confirm before booking.

The form itself is short. The risk is in the details: a consignee spelt two ways, a description too vague for customs, a value that does not match the invoice. Those errors are copied onto the bill of lading and the declaration, and fixing them after the cargo moves costs far more than checking before. AI is good at the copying and the consistency check, and poor at judgement, so give it the copying.

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What the letter does in the shipping chain

The SLI is a written request from you to the forwarder. It does not replace the commercial invoice, the packing list or the bill of lading. It sits ahead of them and is the source from which the forwarder prepares several of them, so a mistake on it spreads.

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Forwarders use their own templates, and some call it shipper's export instructions or booking instructions. The core content is the same. If your forwarder has a form, use it and fill it with the approach below. If you do not have one, a standard layout is easy to build, and the field list in the next section covers what is normally needed.

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Every field on the letter, and what to put in it

The consignee and the notify party

These two get confused most. The consignee is the party named on the transport document as the receiver. The notify party is whoever the carrier should alert when the goods arrive. A buyer who uses a local customs broker will often name the buyer as consignee and the broker as notify party, or the other way round. Do not guess: take the name and address from the buyer's own purchase order or ask them directly. Names should match across the letter, the invoice and any payment documents, down to the legal suffix, because mismatches can hold up a release or a letter of credit payment.

Description and classification

A line that says "parts" or "samples" is not enough. Use what the item is, what it is made of and what it does: "Stainless steel pump housings, machined, for industrial water pumps" rather than "pump parts". The tariff (HS) code is the six-digit classification from the international Harmonized System that customs authorities share, which many countries extend with extra digits for their own tariffs; it decides duty and sometimes whether the goods need a licence. A wrong code can mean the wrong duty, delay or penalties for the importer. Let AI propose a code and the reasoning, then have the forwarder or a customs broker confirm it. If you ship the same product repeatedly, keep the confirmed code in your product record so the question is answered once.

A worked example: a small manufacturer's first export

Take a small business that makes stainless-steel pump housings. An overseas customer has ordered 240 housings in 8 cartons of 30, and the sales order holds everything the letter needs. Illustrative order data:

Order SO-2043
Customer: Example Pumps Ltd (legal name as on contract)
Ship-to: Unit 4, Example Industrial Estate, [city], [country]
Broker named by customer: Example Customs Services
Incoterm: DAP, customer's warehouse
Items: Pump housing, stainless steel 316, machined, model PH-60
Qty: 240 at $38.50 each = $9,240.00
Packing: 8 cartons, each 30 units, 21 kg gross, 56 x 40 x 34 cm
Net weight total: 8 x 19.5 kg = 156 kg
Requested ship date: 14th
Hazard: none. Special: keep dry.

The sums are worth doing by hand. Value: 240 × $38.50 = $9,240.00. Gross weight: 8 × 21 = 168 kg. Net: 8 × 19.5 = 156 kg. Volume: 0.56 × 0.40 × 0.34 = 0.0762 m³ per carton, so 0.61 m³ for eight. These are the figures the forwarder will use for the freight quote, so they must be right.

The prompt

Fill a shipper's letter of instruction from the order data below.

Rules:
- Use ONLY the order data. Never invent a value, address, code or date.
- If a field is not in the data, write "TO CONFIRM" in that field.
- Copy names and addresses exactly as given. Do not tidy or abbreviate.
- Calculate totals (value, gross weight, net weight, volume) and show the working.
- For the tariff code, give your suggested 6-digit code and one sentence of
  reasoning, labelled "SUGGESTION - forwarder to confirm".
- After the letter, list "Checks for the forwarder": any mismatch between fields,
  anything that looked incomplete, and anything that might make the goods
  restricted or need a licence.

Fields: shipper; consignee; notify party; origin; destination; trade term;
description; tariff code; packages; weights; dimensions; value and currency;
dangerous goods; special instructions.

Order data:
[paste order]

Illustrative output (trimmed): the letter with the totals shown above, "Notify party: TO CONFIRM (the order names a broker but gives no address)", "Tariff code: SUGGESTION - forwarder to confirm: a code in the pump-parts group, as the housing is a machined component for pumps", and a checks list that includes "Dangerous goods: order says none; stainless housings are not normally classed as dangerous, but confirm packaging does not include oils or coatings". The assistant has done the copying and arithmetic, and marked three places where a human must act. That is exactly the shape you want.

Where the output goes wrong

Check these every time. They are the failures that actually show up.

• Silent tidying. The assistant corrects "Example Pumps Ltd" to "Example Pumps Limited". Harmless in a letter, wrong when it must match the buyer's registered name. The prompt rule "copy exactly" reduces it; the check catches it.
• Invented fields. A missing notify-party address gets plausible-looking text. The "TO CONFIRM" rule prevents most, but scan every line for anything you did not provide.
• Unit slips. Weights in kilograms mixed with pounds, or centimetres treated as inches, produce a volume that is wrong by a large factor. State the units once at the top and check the total against a rough sum in your head.
• Overconfident codes. The assistant gives a code as if settled. The label SUGGESTION is the guard. A quick cross-check is to ask the same question in a second assistant, and to look the heading up on an official tariff page. If they differ, the forwarder decides.
• Value mismatch. The letter and the commercial invoice differ by a discount or a freight line. Customs compares them. See cross-checking the commercial invoice and packing list to make this check routine.

What the forwarder checks, and how to make it easy

You are not sending the letter to be rubber-stamped. The forwarder is looking for things you cannot see: whether the code matches how they usually classify the goods, whether the destination needs a licence or a certificate of origin, whether the consignee is on a restricted-party list, whether the trade term and the booking agree, and whether the cargo fits the service you asked for. Make their job easy with a one-paragraph cover note:

Subject: Booking request, SO-2043, 8 cartons, ready 14th

Hi [first name],

Attached is our letter of instruction for the pump housings, with the
commercial invoice and packing list. Three items I am not sure about:
1. Tariff code: our suggestion is on the letter, please confirm.
2. Notify party address: the customer's broker has not sent it yet.
3. Whether any export licence or certificate of origin applies.

Cartons will be ready for collection on the 14th, access to the dock is
8:00 to 16:00. Please reply with the confirmed letter or your corrections.

Thanks,
[your name]

When the corrections come back, use them. Ask the assistant to compare your original letter and the forwarder's version and list every difference. Then update your master records: the confirmed code, the notify party, the description wording. A letter that starts correct next time is where the saving is. For a wider look at other documents in the set, see AI tools for shipping documents.

Setting up the master data once

The quickest gain comes before any letter is written. Build one sheet for parties and one for products. The parties sheet holds each customer's legal name exactly as on the contract, address, contact, notify party, broker and usual trade term. The products sheet holds the approved description, the confirmed tariff code, net and gross weight per unit and carton size. Then the prompt pulls from these sheets and the order supplies only quantities and prices. Setting up a dozen products takes an afternoon, mostly spent confirming codes with the forwarder, and from then on a letter is mostly a lookup. Review the sheets twice a year, and whenever a customer changes address or a product changes material.

How the trade term changes what you write

The agreed Incoterms rule decides who pays for and arranges each leg, so it changes what the forwarder needs from you and what they quote. A simplified picture, for orientation only, because the exact obligations come from the rule text and your contract.

If the order data does not state the term, the right move is to mark it TO CONFIRM and ask the buyer, not to let the assistant pick one. A letter that says DAP while the contract says FCA can start a dispute about who owes freight.

From a spreadsheet of orders to a batch of letters

Many exporters ship weekly, and the order data already lives in a sheet. Instead of pasting one order at a time, export the week's rows and ask the assistant for one letter per order number. Keep the prompt above and add: "Produce one letter per order. Do not combine orders, and do not carry any field from one order into another." The second sentence matters more than it looks, because cross-contamination between orders (one buyer's notify party appearing on another's letter) is a typical batch failure.

A second illustrative order shows how the checks work. Suppose row 2 reads: "SO-2044, same customer, 100 housings at $38.50, DAP, notify party blank, 4 cartons of 25." The assistant should produce a value of $3,850.00 and a letter whose notify-party field says TO CONFIRM, not a copy of SO-2043's broker. Its checks list should also say "Cartons hold 25 units here but 30 on SO-2043: confirm the packing change." That is a useful catch, since a changed carton size changes weight and volume and therefore the freight cost.

After any batch run, spot-check three letters in full and every letter for value, quantity and consignee. If one error appears in the three, check them all.

Comparing your letter with the forwarder's corrected copy

The second pass is as valuable as the first. When the forwarder sends back a corrected version, paste both and ask for the differences:

Compare my original letter with the forwarder's corrected version.
List every difference as: field, my value, their value.
Then say which differences are corrections of errors on my side
(spelling, code, missing detail) and which are changes of instruction
(date, service, route). Do not judge who is right.

Illustrative result: "Tariff code: mine 8413.91, theirs the same 8413.91 subheading extended to the full national code (correction: missing digits). Description: mine 'pump housings', theirs 'stainless steel pump housings, machined' (correction). Ship date: mine 14th, theirs 15th (change of instruction; confirm with the carrier)." Each correction is then written back to the product record, so the description and code are right the next time. This is the loop that makes the process improve rather than just repeat.

Who is responsible for what

It helps to be clear about roles, because the letter is a statement made in your name. You, the shipper, are responsible for the accuracy of the information you give: what the goods are, their value, who receives them. The forwarder prepares documents from your instructions, books space and, if you authorise them, files declarations on your behalf, but they rely on what you tell them. The carrier moves the cargo and issues the transport document. The buyer is responsible for import clearance in most trade terms. An assistant is none of these. It prepares a draft, and your signature is what makes the draft a statement.

That is why the signing step should never be automated, and why the checklist above ends with a named person. If you are unsure whether a statement on the letter is accurate, leave it as TO CONFIRM and ask. Penalties for wrong declarations differ by place and are not something to learn about after the fact; an adviser or a customs broker can explain the rules that apply to your goods and your route.

Keeping a copy and an audit trail

Keep the signed letter, the version the forwarder confirmed, the invoice and the packing list together in one folder per shipment, named by order number and date. If a shipment is queried months later, you need to show what you instructed and what was confirmed. Retention periods for trade records vary by place and by document, so ask your forwarder or an adviser how long you must keep them; do not rely on an assistant's answer.

A tidy habit is a one-line log: date, order number, forwarder, what changed after review, who signed. After a dozen shipments, that list shows which fields get corrected most, and those fields become the ones you automate carefully.

Four other shipments, four different problems

The same letter changes shape with the cargo. Quick sketches, all illustrative:

• A craft brand shipping samples. Value is nominal, but "samples, no commercial value" is not accepted everywhere. State a fair value and the reason "for evaluation, not for resale", and ask the forwarder how samples are treated.
• A food producer. Description must be exact (ingredients, form, storage temperature), and import rules may require a health certificate. The assistant can build the description from the product sheet, but only the forwarder and the authorities can say what certificate applies.
• A courier-style repeat route. A courier firm moving the same parcel type each week can keep a standing letter with parties, trade term and handling notes fixed, and only change quantities and values each week. Refresh it every quarter.
• A shipment with batteries or liquids. These can be dangerous goods. Flag any such keyword to a person and do not let the assistant write "none" for you.

For how the forwarder turns your letter into a quote, and how to read it, AI-assisted freight quoting is the other side of the table.

A short checklist before you send

1. Names and addresses match the purchase order exactly.
2. Notify party is confirmed or marked TO CONFIRM.
3. Trade term and named place match the contract.
4. Description would make sense to someone who has never seen the product.
5. Tariff code is labelled as a suggestion, or confirmed.
6. Values, quantities and weights match the invoice and packing list, and the totals are recalculated.
7. Dangerous goods, temperature and handling are stated, not left blank.
8. A named person signs and dates it.
9. A copy is saved to the shipment folder before it is sent.

That list takes about three minutes. With the prompt and the master data in place, most of the typing disappears and the check becomes the main job. Time your first few letters before and after so you know what it saves you, but treat a forwarder who finds nothing to correct as the better measure of success. If your forwarder corrects the same field three times, change the prompt or the master record, not just the letter.

Finally, remember what the assistant cannot know: the buyer's real name as registered, the destination's current rules, whether your goods need a licence, and whether a party is restricted. Those are checks for the forwarder, a broker or an adviser, and the letter is where you ask for them in writing.

Letter of instruction questions from first-time exporters

Is a letter of instruction the same as a bill of lading?

No. The letter of instruction is your written request to the forwarder: what is moving, to whom, how and what to do. The bill of lading is the carrier's contract and receipt, and is issued afterwards. Errors on the letter tend to be copied onto the bill, which is why it is checked first.

Who signs the letter?

The shipper, or someone with authority to sign for the company. Many forwarders also ask for a signed authorisation to act on your behalf for filings. Ask your forwarder what they require, and keep a signed copy of each letter.

Do I need a new letter for every shipment?

Usually yes, because goods, values, consignee and dates change. Some forwarders accept a standing letter for repeat shipments on the same route with the same parties. Check with yours, and refresh a standing letter whenever any party or term changes.

Can AI choose the tariff code?

It can suggest a code and the reasoning, but the code decides duty and what rules apply, so treat any AI suggestion as a draft. Confirm with your forwarder, a customs broker or the official tariff database before it goes on a letter.

What should I do with the forwarder's corrections?

Update your master data, not just this letter. If the forwarder fixes the notify party or a description, write the fix back to your customer record so the next letter starts correct.

Further reads

• Can AI Check Customs Compliance? What a Person Must Still Verify — What a person must still verify on the customs side.
• AI for Customs Brokers: Draft Client Updates and Entry Checks — What the broker sends back once the shipment is filed.
• Advance Shipping Notice: Prepare an ASN From Pick Lists With AI — Prepare the paperwork that follows a pick list.
• Demurrage and Detention: AI Tracks Free Days and Drafts Disputes — Track free days once the container is moving.
• AI for Shipping Companies: Courier Quotes, Tracking Replies and Claims — Courier quotes and tracking replies for smaller parcels.
• AI Tools and AI Development: The Complete 2026 Guide — the AI hub, including every tutorial in the AI-for-business series.

Sources: forwarder and carrier shipper's-instruction guidance (field lists vary by forwarder); WCO (wcoomd.org), What is the Harmonized System; ICC Academy, Incoterms 2020: EXW or DDP (clearance duties under EXW, FCA, DAP and DDP); the USITC Harmonized Tariff Schedule for subheading 8413.91 (parts of pumps). All quantities, values and party names are illustrative.