How to Work with Shippers Without a Master Trading Agreement

Overview

In freight forwarder operations, transactions sometimes proceed based only on quotes, emails, booking requests, and invoices, without signing a basic transaction agreement with the shipper.

For spot jobs, small-scale shippers, referral cases, urgent shipments, or shipments via overseas agents, it is not uncommon for operations to begin before a formal contract is finalized.

However, when incidents, additional costs, delivery delays, insurance not arranged, B/L name disputes, unpaid Freight Collect, Demurrage, Detention, or Survey fees arise without a contract, it becomes difficult to explain responsibility scope and cost allocation.

This article organizes how a freight forwarder should establish at least minimum defenses through quotes, emails, standard trading conditions, FCR, insurance confirmations, and additional cost terms when dealing with shippers without a transaction agreement.

Scope Covered in This Article

This article covers how freight forwarders should document cost scopes, responsibility limits, insurance presence, instruction changes, additional charges, and the application of standard trading terms when transacting with shippers without a basic contract.

Item	Content Covered in This Article	Content Covered in Other Articles / Separate Checks
Transactions without basic contract agreements	Methods to create minimum defenses through quotes, emails, FCR, and standard trading terms when no contract exists.	Contract drafting, negotiation, and legal effectiveness require expert confirmation.
Marine Cargo Insurance	Whether insurance is included in the quote, arranged by the shipper, or not arranged, and how to record this.	Insurance terms, premium, payout eligibility, and Survey arrangements are covered in the marine cargo insurance article or insurance company consultation.
Additional Costs	How to record demurrage, detention, storage, inspection fees, redelivery charges, etc., as separate actual costs.	Calculation methods, exemption negotiations, and occurrence day checks are covered in individual articles.
Freight Collect	The necessity to record who can be billed if Freight Collect is unpaid via quotes and order confirmation emails.	Details on unpaid Freight Collect, D/O release, and shipper billing are covered in separate articles.
No Show Cargo	The necessity to record cancellation fees or Dead Freight conditions in case cargo does not ship after booking.	Analysis of causes, cost billing, rebooking on next vessel, and credit issues for No Show are treated in other articles.
Survey & Claim Letter	Because Survey fees and notification obligations become issues during incidents, their relationship with standard trading terms is covered.	Surveyor arrangements, Survey Reports, Claim Letter wording, and notification deadlines are covered elsewhere.

Not Uncommon to Have No Contract

In international logistics operations, it is not always possible to start transactions only after signing a formal basic transaction contract with every shipper.

In cases such as introductions from existing customers, one-time shipments, urgent loading, exhibition cargo, sample shipments, or small imports, quotes and arrangements may precede formal contracts.

Therefore, simply deciding "no contract means no transaction" is not practical.

What is important is that even without a contract, cost scope and responsibility scope should be clarified as much as possible through quotes, emails, standard trading terms, FCR, instruction confirmations, and internal records.

Common Troubles When There’s No Contract

When there is no basic transaction agreement, the following troubles often arise after incidents or additional costs occur.

Issue	Troublesome Points	Records to Keep in Advance
Disputes over quote scope	Arguments arise over what is included in the quoted price and what is considered extra cost.	Specify transport segments, cost scopes, separate actual costs, and quote validity period in the quote.
Disputes over additional cost liability	Demurrage, detention, storage, inspection fees, and redelivery costs can cause issues.	List concrete cost items subject to additional actual charges.
Disputes over insurance not arranged	The shipper may misunderstand that insurance is included.	Record presence or absence of marine cargo insurance, that premiums are not included, and that the shipper is responsible for arranging insurance.
Scope of freight forwarder liability	Arguments occur over whether the freight forwarder has carrier responsibility or only arranging responsibility.	Clarify standard trading terms, FCR, B/L conditions, and scope of operations.
Delivery delays and consequential loss	Claims for lost sales, production stoppages, and penalties due to late delivery may be made.	Clarify non-warranty of delivery time, force majeure, third-party circumstances, and limitation of liability.
B/L name and correction disputes	Issues arise related to Shipper, Consignee, Notify Party, Surrender, and Sea Waybill changes.	Confirm B/L instructions, correction requests, responsible parties, cut-off times, and additional costs by email.
Poor packaging or insufficient cargo information	Lack of declaration regarding dangerous goods, weight, dimensions, temperature conditions, or fragility causes problems.	Confirm the shipper's obligation to declare cargo details, dangerous goods status, and packaging responsibility.
Starting point of responsibility after FCR issuance	There may be disputes over when, where, and in what condition cargo was received.	Keep FCR, receipt records, photos, loading records, and standard trading terms on file.

Without a contract, these issues need to be interpreted from individual emails, quotes, FCRs, and standard trading terms. Therefore, how records are maintained daily is critically important.

Defensive Documentation With and Without Contracts

If there is a basic transaction agreement, you can explain the scope of responsibility, additional costs, insurance, claim deadlines, payment terms, etc., based on the contract. If there is no contract, the quotation, email, FCR, standard terms and conditions, invoice, and booking records serve as practical defense documents.

Defense Document	Role When There Is a Contract	Role When There Is No Contract	Practical Notes
Quotation	Shows individual conditions and amounts based on the contract.	Acts as an entry point to show the scope of costs, separate actual expenses, insurance coverage, and applicable conditions.	Create it as a defense document, not just a price list.
Email	Records individual instructions and change history under the contract.	Serves as evidence for substantive agreements, instructions, approvals, changes, and warnings.	Always keep confirmation emails after phone calls.
Standard Terms and Conditions	Functions as conditions complementing the contract.	Provides the basis for explaining limits of liability, exclusions, claim deadlines, additional costs, and shipper obligations.	Present in a way that the shipper can confirm them.
FCR	Acts in conjunction with the contract as proof of cargo receipt.	Links the cargo receipt time, place, condition, and standard terms and conditions.	Important to present the conditions on the back of the FCR or the standard terms and conditions.
Booking Confirmation	Confirms individual transportation terms based on the contract.	Records vessel name, cut-off times, cost terms, cancellation conditions, and no-show policies.	Accurately forward to the shipper and keep their approval.
Invoice	Billing document based on the contract and quotation conditions.	Supports occurrence basis for additional costs and third-party actual expense billing.	Explain the cause of charges along with the invoice.

Using the Quotation as the Entry Point for Contract Terms

In transactions with shippers without a basic transaction agreement, the quotation serves as the entry point for contract terms.

The quotation should not simply list prices but clearly state the transport segment, scope of costs, separate actual expenses, validity period, presence or absence of insurance, conditions for additional charges, and applicable clauses or standard terms and conditions.

For example, phrases like "Marine cargo insurance is not included in this quotation" or "Customs inspections, storage fees, Demurrage, Detention, and additional costs due to consignee circumstances will be actual expenses extra when incurred" serve as explanatory notes for later reference.

Without a contract, the quotation functions not as a mere price list but as a defense document.

Utilize Standard Terms and Conditions When There Is No Basic Transaction Agreement

If there is no basic transaction agreement, the freight forwarder needs to make use of standard terms and conditions.

It is not practical to conclude individual contracts with every shipper. However, accepting work without any stated conditions or contracts means that, after an incident, responsibility scope, exclusions, liability limits, claim deadlines, and additional costs will have to be negotiated from zero.

Therefore, at a minimum, it is important for the company to prepare standard terms and conditions and present them in a way the shipper can verify, such as through quotations, Booking Confirmations, FCRs, emails, websites, or PDF attachments.

Especially for NVOCC CLUB members and independent freight forwarders, issuing FCRs and presenting standard terms and conditions are important defensive measures. The FCR not only indicates the fact of cargo receipt and the start of responsibility but also organizes the scope of the freight forwarder’s liability by linking the back-side conditions or the standard terms and conditions.

Having standard terms and conditions makes it easier to explain at the time of an incident "what scope of responsibility applies," "which damages are excluded or limited," "how claim deadlines are handled," and "how indirect or delay damages are treated."

Conversely, without presenting either standard terms and conditions or FCRs, it becomes unclear from what position the freight forwarder accepted the cargo and to what extent liability was assumed.

Practical Meaning of Using FCR

The FCR is a document showing that the freight forwarder has received the cargo. It may be used for domestic pickup, warehouse delivery, before or after CFS entry, receipt from subcontracted carriers, or start of storage at a designated warehouse.

When there is no basic transaction agreement, the FCR becomes an important record showing when, where, and in what condition the cargo was received.

In addition, incorporating the standard terms and conditions into the FCR makes it easier to explain responsibility scope, exclusions, liability limits, claim deadlines, and obligations of the shipper to provide information after cargo receipt.

For example, even if no individual contract was signed with the shipper, if the standard terms and conditions were presented at the time of FCR issuance, then after an incident there is a certain basis for explaining compensation liability limits and claim deadlines.

The FCR is not just a receipt. In transactions without a contract, it serves as a practical defense document linking the fact of cargo receipt and the standard terms and conditions.

Preserving Agreement Content by Email

Email is extremely important in transactions without a contract.

Requests from shippers, quotation approvals, Booking instructions, B/L information, delivery locations, insurance arrangements or absence thereof, acceptance of additional costs, and change instructions should all be documented by email as much as possible.

Even when receiving instructions by phone or verbally, sending an email such as "Based on our earlier phone conversation, we will proceed with arrangements under the following conditions" allows at least the freight forwarder's understanding to be recorded.

Without a contract, accumulated emails effectively become the substantive contract terms. That said, it does not mean emails alone are sufficient. It is important to combine them with quotations, standard terms and conditions, FCRs, invoices, and internal records.

Clearly Stating Applicable Clauses

Even when there is no basic transaction agreement, it is important to specify in quotations or emails that the freight forwarder’s standard terms and conditions or clauses will apply.

For example, include statements such as "Our standard terms and conditions apply to this transaction" or "Handled based on our clauses."

However, simply having the terms and conditions internally is not sufficient. Terms and conditions that have not been shown to the shipper or whose location is unknown can become points of dispute later.

It is preferable to make them available in a form that the shipper can confirm, such as in a quotation, email, FCR, web page, or attached PDF.

Always Confirm Whether Marine Cargo Insurance Is Included

One of the biggest risks in transactions with shippers without a contract is misunderstandings about marine cargo insurance.

The shipper may assume “insurance is included because transport was requested,” while the freight forwarder believes “no insurance request was received.”

Such misunderstandings can lead to major troubles after an accident occurs.

Therefore, it is important to confirm in quotations or emails phrases like “Marine cargo insurance is not included,” “Please request insurance separately if needed,” or “The shipper is responsible for insurance arrangements.”

It is also necessary to keep a record when insurance arrangements are not made.

Do Not Leave Additional Charge Conditions Ambiguous

Additional charge conditions tend to become ambiguous in transactions without contracts.

Charges such as customs inspection, storage fees, demurrage, detention, waiting charges due to consignee convenience, redelivery fees, small vehicle handling fees, and holiday delivery fees are prone to disputes with the shipper when they arise.

Clearly stating in quotations or emails that these charges are “extra costs charged at actual occurrence” is important.

This prior explanation is indispensable, especially for import cases where charges often arise from customs delays, D/O exchange delays, consignee issues, or exceeding free time.

Do Not Broaden Your Responsibility Scope Excessively

In the absence of a contract, freight forwarders may sometimes unintentionally accept overly broad responsibilities by email or verbally.

Expressions such as “We take full responsibility,” “We will handle anything,” or “We guarantee no issues until delivery” should be avoided.

Freight forwarders arrange transport, customs clearance, domestic delivery, document handling, etc., but they are not in a position to guarantee everything including shipping lines, CFS, customs, delivery companies, consignees, packing by the shipper, or information provision.

Especially in deals without contracts, caution is needed not to expand the scope of responsibility through email wording.

Scope of Freight Forwarder / NVOCC Involvement

In transactions with shippers without a master agreement, it is necessary to distinguish what freight forwarders / NVOCCs can easily support and what should not be conclusively stated. This is particularly important regarding responsibility scope, additional charges, insurance, delivery schedule, B/L corrections, and compensation in case of accidents, where definitive statements should be avoided.

Situation	Actions Easily Supported	Statements That Should Not Be Made	Practical Advice
Clarifying Quotation Terms	Clearly state transportation section, cost scope, extra charges at actual cost, and whether insurance is included.	Avoid explanations implying all costs not included in the quotation are covered.	Separate out included and additional charges in writing.
Transport Arrangements	Arrange shipping line, NVOCC, customs, delivery, CFS, etc.	Do not guarantee third-party operations or schedules absolutely.	Distinguish between planned, expected, and pending confirmations.
Insurance Confirmation	Confirm whether marine cargo insurance is included or if insurance arrangement is requested.	Avoid stating “insurance is included” without confirming insurance.	Note in the quotation whether insurance cost is included or excluded.
Accident Response	Support survey, Claim Letter preparation, photographic records, and notifications to related parties.	Avoid definitive statements such as “We will fully compensate” or “We take all responsibility.”	Investigate cause, responsibility scope, and insurance before responding.
B/L Information Confirmation	Organize shipper, consignee, notify party, surrender, and sea waybill information.	Do not unilaterally change the consignee or conditions without shipper’s instructions.	Keep B/L instructions and correction requests documented via email.
Charging Additional Costs	Organize invoices, reason for occurrence, third-party charges, and timeline.	Do not assume all extra costs are automatically borne by the shipper without prior agreement.	Document extra costs separately in quotations and send warning emails.
Suggesting Contract Conclusion	Propose concluding a master service agreement in ongoing or high-value transactions.	Do not mechanically refuse all transactions without a contract.	Decide based on case scale, transaction frequency, and risk.

Minimum Checks Before Transactions

Even when dealing with a shipper without a master service contract, there are minimum points that must be checked. Proceeding without confirming these points may complicate responses in case of accidents or nonpayment.

Check Items	Reason for Confirmation	Practical Notes
Official name, location, and contact person of the shipper	Clarifies the billing party, contracting party, and contact information.	Avoid proceeding only with trade names, department names, or personal names.
Billing party and payment terms	Specifies the collection destination in case of non-payment.	Consider advance payment or payment confirmation for first-time transactions.
Cargo description, value, and hazardous material status	Confirms transport feasibility, insurance necessity, and declaration obligations.	Avoid arranging shipments with ambiguous cargo descriptions.
Transportation route and delivery terms	Clarifies scope from origin to destination responsibility.	Confirm collection, customs clearance, delivery, and unloading conditions separately.
Customs declaration name and importer name	Identifies who is responsible for customs clearance and document preparation.	Verify if the importer is the shipper themselves or another company.
Presence of cargo insurance	Prevents issues related to recovery methods after accidents and troubles from uninsured shipments.	Clearly state whether insurance costs are included in the quotation.
Conditions for bearing additional costs	Organizes potentially contentious costs in advance.	Specify customs inspections, storage, demurrage, and detention charges.
Applicable terms and conditions / standard trading conditions	Serves as the basis for liability scope, exclusions, liability limits, and claim deadlines.	Present in a way that the shipper can confirm.
Issuance of FCR	Records the timing and condition of cargo receipt.	Confirm the linkage with standard trading conditions.
Methods for accepting change instructions	Prevents confusion regarding B/L corrections, delivery destination changes, and surrender instructions.	Confirm changes by email even after telephone instructions.

Keep Thorough Records Especially for Spot Transactions

For shippers with ongoing transactions, aspects can be supplemented by past communications and operational track records.

On the other hand, with spot transactions or first-time deals, the counterpart's operational proficiency, payment attitude, cargo specifics, insurance awareness, and understanding of additional costs are unknown.

Therefore, especially for spot transactions, it is necessary to clearly document quotation terms, presence or absence of insurance, extra costs, payment terms, delivery conditions, and application of standard trading conditions.

Rather than “simplifying because it’s only one time,” adopting the mindset of “precisely because it’s only one time, keep thorough records” is important.

Common Misunderstandings

Common Misunderstanding	Actual Perspective	Practical Notes
Do not do business with a shipper who lacks a basic trading agreement.	In spot or urgent transactions, business may start without contracts.	Use quotes, emails, standard trading conditions, and FCR to establish a minimum protective layer.
For a one-time shipment, it is okay to be simple in confirming terms.	For initial or spot deals, the counterpart’s operational understanding and payment stance are unclear.	Precisely because it’s a one-time transaction, records should be kept.
Email agreements alone are sufficient.	Emails are important, but need to be supplemented with standard trading conditions, quotation terms, and FCR.	Do not rely solely on emails; clearly document application of terms and cost conditions.
A quotation only needs to state the amount.	When there is no contract, quotations become important documents indicating cost and liability scope.	Include separate actual costs, presence or absence of insurance, and applicable terms.
Having standard trading conditions internally is sufficient.	If the shipper cannot confirm the terms, disputes may arise later.	Present terms via quotation, email, FCR, website, or PDF so that the shipper can confirm.
Cargo insurance is automatically included if transport is requested.	Cargo insurance often requires separate arrangements and is not always included in quotations.	Clearly state whether insurance fees are included or not.
If the forwarder says “we’ll handle it,” they assume full responsibility.	Practical handling and legal assumption of responsibility are different.	Avoid expressions like “guarantee” or “take full responsibility.”
Even without a contract, problems can be resolved through discussion after an accident.	After an accident, conflicts of interest arise, making explanations difficult without prior records.	Pre-accident quotations, emails, FCR, and standard trading conditions are crucial.

Cases That Often Cause Issues in Practice

Case	Common Issues	Documents to Check	Practical Notes
Marine cargo accident occurred without insurance arranged	Shipper may claim "insurance is included in the all-in transport service."	Quotation, order confirmation email, insurance confirmation email, cargo value	Clearly state in the quotation that insurance fees are not included.
Demurrage/Detention charges incurred	Disputes arise over whether it is included in the quote or billed separately at cost.	Quotation, Free Time notice, shipping line invoice, warning emails	Explicitly specify separate billing by actual cost for each applicable charge.
Freight Collect could not be collected	Issues arise whether unpaid charges by consignee can be charged to shipper.	B/L, quotation terms, booking email, Arrival Notice	Confirm in advance shipper’s liability in case of non-payment.
Cancellation fee incurred due to No Show Cargo	It becomes difficult to justify fees when cargo was never shipped.	Booking Confirmation, Cut-off notice, cancellation communication, invoice	Specify No Show cost responsibility clearly at booking.
Dispute over who bears Survey fees	Whether accident response costs are normally included in the quotation is disputed.	Survey estimate, insurance company correspondence, standard trading terms, accident records	Include handling of accident response actual costs in standard trading terms.
Trouble over B/L name changes or Surrender instructions	Disputes occur over whose instruction led to name change or surrender.	B/L instruction emails, correction requests, surrender requests, shipping line records	Always keep B/L-related instructions in writing via email.
Damage discovered after FCR issuance	Timing and condition at receipt of cargo become disputed points.	FCR, receipt photos, packing condition records, standard trading terms	Link FCR issuance clearly with the standard trading terms.
Unclear billing party leads to non-payment	It is unclear whether bill should be sent to shipper, importer, referrer, or overseas agent.	Quotation request, order confirmation email, billing confirmation, payment terms	Confirm official company names, billing party, and payment terms before order acceptance.

Decision-Making Checklist

Confirmation Stage	Who to Confirm With	Items to Confirm	Actions if Issues Arise
At Quotation Request	Shipper, Sales representative	Official company name, cargo details, transport route, desired terms, billing party	If billing party or client is unclear, confirm before preparing the quotation.
When Submitting Quotation	Shipper	Cost scope, additional charges billed separately, insurance included or not, validity period, standard trading terms	Clearly state not only prices but also conditions.
At Order Acceptance	Shipper, overseas agent	Quotation approval, booking instructions, payment terms, insurance arrangement, additional cost conditions	Record confirmation of conditions in order acceptance email.
At Booking	Shipper, shipping line, NVOCC, airline	Booking number, cut-off, cancellation conditions, No Show costs, B/L information	Provide accurate Booking Confirmation to shipper.
At Cargo Receipt	Shipper, warehouse, delivery company, CFS	Receipt date, receipt location, packing condition, quantity, FCR issuance	Keep FCR and photographic records as needed.
At Change Instructions	Shipper, consignee, overseas agent	B/L corrections, delivery address changes, surrender, switch to Sea Waybill, cost responsibility	Do not act on verbal instructions alone; keep confirmations by email.
When Additional Charges Occur	Shipper, shipping line, warehouse, customs broker, delivery company	Reason for charges, amounts, duration, third-party invoices, prior warnings	Explain timeline and causes clearly, not just provide invoices.
When Accidents Occur	Shipper, insurance company, NVOCC, carrier, warehouse, delivery company	Insurance presence, survey necessity, claim letter, evidence preservation, liability scope	Do not make immediate liability decisions; preserve records and inform all parties.

Timing to Consider Signing a Contract

It can be difficult to sign a basic trading contract with all shippers from the beginning.

However, when dealing with ongoing business, large transaction amounts, high-value or hazardous cargo, increasing advance payments, or cases prone to accidents or additional charges, signing a basic trading contract should be considered.

Also, for shippers with whom disputes over cost responsibility or liability have occurred in the past, contract terms should be organized before future transactions.

Contracts are not meant to be cumbersome documents but practical tools to reduce misunderstandings between parties.

Example 1: Dispute Over Unarranged Insurance Without a Contract

In a certain single import transaction, the shipper requested the forwarder to handle sea transport, import customs clearance, and domestic delivery as a package. No basic trading contract was signed; arrangements proceeded based only on quotations and emails.

The quotation included sea freight, D/O fee, customs clearance fee, and domestic delivery charges, but there was no mention of cargo insurance.

After cargo arrival, damage was found during devanning. The shipper claimed, "Since I requested the entire transport service, I assumed insurance was naturally included."

The forwarder explained no insurance arrangement was requested, but there was no email or quotation term clearly stating insurance was not arranged.

As a result, although legal liability was not immediately determined, it caused significant impacts on explanations to the shipper, damage cost negotiations, and continuity of future transactions.

In this case, if the quotation had stated “Marine cargo insurance is not included. Please request separately if needed,” and the shipper’s confirmation of no insurance requirement or separate arrangement had been obtained, the points of contention could have been significantly reduced.

Example 2: A Case Where FCR and Standard Terms Served as Defense Materials

In another domestic collection case, no master contract had been concluded with the shipper. However, the freight forwarder issued an FCR upon cargo receipt, clearly stating on the FCR the application of standard trading conditions.

Subsequently, damage was discovered on the cargo, and the shipper filed a damage claim. The cause of the accident could not be immediately identified as it could have been handling during transportation, inadequate packing, or the shipper’s pre-shipment condition.

At this time, the FCR allowed confirmation of when and in what condition the freight forwarder received the cargo. Also, since the standard trading conditions had been presented, there was a certain basis for explaining liability limitations, exemptions, and claim deadlines.

Ultimately, the forwarder was able to negotiate after organizing the evidentiary relationship and scope of liability, rather than bearing full responsibility.

In this case, having formed a minimum defensive line through the FCR and standard trading conditions was more important than the mere absence of a master contract.

Example 3: A Case of B/L Title Trouble After Transaction Start

In an export case, no master contract had been concluded with the shipper, and booking proceeded through quotations and emails. Initially, the shipper instructed to put its own company name in the Shipper field, but just before loading, the overseas trading partner requested a change to another company name.

Because it was an urgent case, the person in charge took the change instructions by phone and proceeded with the B/L correction without sufficiently securing email confirmation. Later, discrepancies in recognition occurred among the shipper, the overseas buyer, and the bank regarding payment settlement and export document consistency.

The shipper claimed, “We expected the forwarder to handle it correctly,” while the forwarder explained, “We only followed the shipper’s phone instructions.” However, there was insufficient record showing who formally approved which name change and who understood the risks of the change.

In this case, important instructions such as B/L title, Consignee, Notify Party, Surrender, and Sea Waybill switches should always have been confirmed by email regardless of whether a contract existed. Especially in transactions without a contract, handling B/L-related instructions only verbally creates ambiguity about responsibility later.

Practical Points to Note

In transactions without a master contract with the shipper, it is impossible to cover everything by contract. Instead, a combination of quotations, emails, standard trading conditions, FCR, invoices, and internal records must be compiled to be able to explain the situation at a later date.

Particularly, issues such as lack of insurance arrangement, additional charges, B/L title changes, freight collect non-collection, no shows, demurrage, detention, and survey costs tend to cause disputes in contract-less transactions.

What forwarders should avoid is not the absence of a master contract by itself, but proceeding with operations without recording anything, showing any conditions, or confirming anything.

Summary

Transactions with shippers without a master contract are not uncommon in actual logistics practice.

However, the importance of quotations, emails, standard trading conditions, FCR, insurance confirmation, and additional charge terms increases the more there is no contract.

The problem is not the absence of a contract per se, but the lack of any record of the scope of costs, liabilities, insurance arrangements, change instructions, additional charges, and application of standard trading conditions.

Forwarders need to prepare quotations, emails, standard trading conditions, and FCR as defense materials for transactions without contracts, so they can explain when accidents or cost disputes occur. If transactions continue and the amounts or risks grow, it is important to consider concluding a master contract early.