Can a company simply amend its general terms and conditions? The short answer: not always. Amendment clauses in general terms and conditions are legally complex and may be unfair or even void, especially in consumer contracts.
In June 2025, the Amsterdam Court of Appeal ruled once again that unilateral changes without valid reason are inadmissible. This is a crucial signal for entrepreneurs: an incorrectly worded clause can lead to massive refunds, fines and reputational damage.
In this article, you will learn exactly where the legal line is, how to make your contracts ‘Court of Appeal-proof’ and what the differences are between business and private customers.
What are amendment clauses?
To understand what is and is not permitted, we first need to be clear about what we are talking about. A modification clause is a specific clause in the general terms and conditions that authorizes one party (usually the provider or seller) to modify the agreement during its term.
Companies use this tool to remain flexible. After all, the world is changing: raw materials are becoming more expensive, legislation is changing, and business processes are being modernised. Without a modification clause, you would have to enter into a new contract with each customer for every minor adjustment.
Practical example:
“The contractor reserves the right to unilaterally amend these general terms and conditions and the applicable rates at any time. Amendments shall take effect thirty days after notification.”
Such clauses are frequently found in:
- Software licences (SaaS)
- Rental contracts
- Insurance policies
- Energy contracts
- Subscriptions (gym, telecom)
What are amendment clauses?
To understand what is and is not permitted, we first need to be clear about what we are talking about. A modification clause is a specific clause in the general terms and conditions that authorizes one party (usually the provider or seller) to modify the agreement during its term.
Companies use this tool to remain flexible. After all, the world is changing: raw materials are becoming more expensive, legislation is changing, and business processes are being modernised . Without a modification clause, you would have to enter into a new contract with each individual customer for every minor adjustment.
Practical example:
“The contractor reserves the right to unilaterally amend these general terms and conditions and the applicable rates at any time. Amendments shall take effect thirty days after notification.”
Such clauses are frequently found in:
- Software licences (SaaS)
- Rental contracts
- Insurance policies
- Energy contracts
- Subscriptions (gym, telecom)
Two main types of change
Legally, we distinguish between two types:
- The unlimited unilateral amendment clause: This allows party A to amend the terms and conditions ‘at its own discretion’ or without specific reason. This type is subject to close legal scrutiny.
- The limited amendment clause: Here, the authority to amend is linked to objective circumstances. For example: “Amendments are only permitted if the CBS consumer price index rises by more than 3%.”
Legal framework: when is a modification clause unfair?
Dutch legislation protects the weaker party (usually the consumer) against the power of the drafter of the general terms and conditions. The basis for this can be found in the Civil Code (BW), specifically in Articles 6:233 and 6:237.
Article 6:233 BW stipulates that a clause is voidable if it is “unreasonably onerous” for the other party. But when is a unilateral change unreasonable? To answer this question, we refer to the famous lists in the code.
The grey list (Article 6:237 BW)
Amendment clauses are included in the so-called ‘grey list’ (Article 6:237(c) BW). This is highly relevant from a legal perspective. It means that there is a legal presumption that such a clause is unreasonable.
It is up to the entrepreneur to refute this presumption. You must therefore prove that the unilateral amendment is justified and fair in your specific case. If you fail to do so, the court will annul the clause.
The three golden rules for a fair amendment clause
Do you want to pass the court’s test? Then your amendment clause must meet three cumulative requirements:
- Compelling reason
The power to make changes must not be arbitrary. There must be an objective, verifiable reason. Examples include necessary adjustments due to new legislation, demonstrable extreme cost increases, or technological necessity (e.g., an outdated network that is being decommissioned). Vague terms such as ‘commercial reasons’ are not sufficient. - Transparency and communication
Consumers should not be surprised. An unfair term is often one that is unclear about when and why something is changing. You have an active duty to provide information. - Balancing of interests and the right of termination
The change must not disproportionately disadvantage the consumer. Is the change significant? Then the consumer must have the right to terminate (cancel) the agreement free of charge.
Please note: The distinction between B2B and B2C is crucial. In business contracts (B2B), the parties have more contractual freedom and the grey list does not apply directly. However, small businesses (self-employed persons/SMEs) can sometimes still invoke consumer protection under the ‘reflex effect’ if they are in a similar position to consumers.
Recent case law: Amsterdam Court of Appeal [2025]
In practice, the rules are being applied more and more strictly. An illustrative example is the June 2025 ruling by the Amsterdam Court of Appeal. In this case, a large service company was pitted against a group of consumers.
The case
The company, which offers maintenance contracts for heat pumps, included the following clause in its consumer agreement:
“The provider is entitled to adjust the monthly service costs and the terms and conditions annually in line with market conditions. The customer will be informed of this 30 days in advance by e-mail.”
On the basis of this clause, the company increased its rates by 15% and limited its guarantees, citing “general inflation and staff shortages.
The Court’s ruling
The Court of Appeal ruled against this clause. The clause was declared unfair and therefore void. The Court’s reasoning was crystal clear:
- Too broadly formulated: The term “market conditions” is too vague. Consumers cannot infer from this when or to what extent a change may occur.
- No real choice: Although there was an obligation to provide information, there was no explicit right to terminate the contract free of charge for any change detrimental to the customer.
- Arbitrariness: The trader could increase prices at its discretion, without allowing consumers to verify whether the increase was proportionate to the actual cost increase.
💡 Key consideration of the Court:
“A change clause that gives the provider the discretionary power to amend key terms of the contract, without clear frameworks or a real exit option for the other party, disrupts the contractual balance unacceptably.”
Consequences for the company
The ruling had significant consequences. The company had to reverse the rate increase for all current contracts and refund any excess amounts paid. In addition, the company suffered considerable reputational damage, and all terms and conditions had to be rewritten immediately.
What this means for your company:
- Vague terms such as “market conditions” will definitely be a “no-go” in 2025.
- In the event of substantial changes, an ‘opt-out’ (cancellation option) is mandatory.
- Even if you have been using the same terms and conditions for years, this does not guarantee future compliance.
Checklist: How do you make your amendment clause legally valid?
Do you want to change your general terms and conditions or draw up a solid amendment clause without legal risks? Use this checklist to check your clauses against the current state of legislation and case law.
✅ 1. Specify permitted reasons for change
Be specific. Avoid terms such as ‘at our discretion’ or ‘if we deem it necessary’. Use objective grounds such as: ‘in the event of legislative changes’, ‘in the event of an adjustment to the VAT rate’ or ‘if the CBS indexation increases by X%’.
✅ 2. Build in a communication protocol
Record how you will communicate the change. For consumers, a simple notice on the website is insufficient. You must inform the customer personally and in writing (e.g. by email) at least one month before the effective date.
✅ 3. Guarantee the right of termination
This is your safety valve. If you change the terms and conditions, explicitly give the customer the right to terminate the agreement free of charge on the date the change takes effect. This restores the balance in the contract.
✅ 4. Limit the scope
A clause that states “we may change anything” is inherently suspicious. Limit the authority to specific parts, such as the terms of service or procedural rules. Unilaterally changing core obligations (such as the delivery of the main product) is very risky.
✅ 5. Test the balance of interests
Ask yourself: Is this change proportionate? Is the disadvantage to the customer in proportion to the interests of your company? If not, you run the risk of a court overturning it.
✅ 6. Distinguish between B2B and B2C
You have much more freedom in contracts between large companies. Therefore, consider using two sets of terms and conditions: one set for consumers (strict, compliant) and one for business customers (more flexible).
✅ 7. Document everything
Are you implementing a change? Record why you are doing so in an internal file and keep evidence of the communication to your customers. If a dispute ever arises, you will be in a stronger position with a good file.
✅ 8. Have it legally reviewed
Consumer law is constantly changing. A clause that was fine in 2020 may now be on the grey or black list. Have a specialist screen your terms and conditions periodically.
🔍 Quick self-test:
Read your current amendment clause and ask yourself:
- Would I find this fair and transparent if I were the customer?
- Are the reasons for the change specific enough for an outsider to verify?
- Does the customer have an easy way out if they disagree?
If you answer ‘no’ or ‘doubtful’ to any of these questions, action is required.
Frequently asked questions (FAQ)
1. Can I change my terms and conditions without reason?
No, in principle not. Certainly in consumer agreements, a change without a valid, specified reason is quickly considered unfair. You must have an objective justification for the change, unless the customer explicitly agrees to the new terms and conditions.
2. Do I have to inform customers in advance about changes?
Yes, this is a strict requirement. You have an active duty to provide information. For consumers, you must communicate the change in a timely, clear manner (usually at least one month in advance). A message on your website is generally not sufficient; you must contact the customer individually, for example, by email.
3. What happens if my amendment clause is found to be unfair?
If a court rules that the clause is unfair, it will be annulled (declared null and void). Legally, this means that the clause never existed. Any changes you have made based on that clause are then unlawful. You must refund any price increases and the old terms and conditions continue to apply.
4. Is there a difference between B2B and B2C contracts?
Yes, there is a big difference. The legislator assumes that consumers need extra protection against professional parties. In B2B (business-to-business) relationships, there is more freedom of contract. Please note: small entrepreneurs (self-employed persons) sometimes enjoy similar protection to consumers through a ‘reflex effect’.
5. Can I automatically index prices to inflation?
Yes, a price adjustment clause based on an objective index (such as the CBS Consumer Price Index) is generally permitted. This is not considered an arbitrary price increase, provided that it is clearly agreed which index will be used and how the calculation will work.
What if a customer objects to a change?
If you make significant changes to the terms and conditions, in most cases, the customer has the right to terminate (cancel) the agreement free of charge as of the date the change takes effect. You cannot force the customer to accept the new terms and conditions without offering this option.
7. Do I have to make existing customers comply with new terms and conditions?
Not automatically. In principle, a change to your general terms and conditions only applies to new agreements. For current contracts, you therefore need that specific, legally valid amendment clause to declare the latest set of rules applicable to existing customers.
8. How often can I change my terms and conditions?
There is no legal maximum, but reasonableness and fairness play a role. Frequent changes without justification undermine legal certainty and may be deemed unreasonable by a court. Stability in the contractual relationship is the starting point.
Conclusion: Avoid nullity and reputational damage
The legal reality surrounding amendment clauses in general terms and conditions is clear: the days when companies had carte blanche to amend contracts unilaterally are over.
- An amendment clause is permitted, but subject to strict conditions.
- The burden of proof for the fairness of the clause lies with you as an entrepreneur.
- Recent Court of Appeal case law indicates that judges are ending vague clauses.
- A prior legal review is often cheaper than compensation payments afterwards.
- Did you draw up your general terms and conditions more than two years ago? There is a good chance your amendment clauses no longer meet the 2025 standards.
Do you have questions about your amendment clauses or would you like to have your general terms and conditions reviewed?
Please contact Law & More for a no-obligation consultation. Our corporate law specialists closely monitor the latest developments in legislation and case law and will be happy to advise you on a legally watertight strategy.
