Can you explain the illegal big mistake?

Dealers can do that in the event of pricing mishaps

If you spot it, you will of course access it immediately. Be it the notebook for 150 euros instead of 1,500 euros or the first-class flight to Dubai for 399 euros. Because these system errors are not so rare when quoting prices on the Internet, they have even earned a name of their own: the so-called error fares. An error fare is a price error that arises if, for example, an error occurs in the listing of a product or flight. Often these offers are only so cheap because the provider has not even noticed that he has made a mistake.

Because such errors are occurring more and more frequently, special platforms and bargain hunters on the Internet are even looking for incorrect price information. In order to make it really worthwhile, the wrongly labeled goods are usually ordered in large quantities straight away.

Dealers usually only notice this misery when it is too late and the entire inventory has been sold - at the wrong price. As soon as the mistake is noticed, it gets exciting, because customers who are happy with their bargain do not give up easily. The threat “Then I'll sue it!” Quickly crosses the lips. We have summarized below which rights dealers actually have in such a case.

The expensive bargain

Our editorial team received this request at the end of last week: “Yesterday I ordered three tablets from Shop XYZ at a single price of 119.00 euros and also received three order confirmations. Originally these were shown at a price of around 1,500 euros. Now I received three new e-mails in which the dealer is contesting the sales contracts [...]. ”(Editor's note: The facts have been shortened for better illustration.)

Only a binding contract is required to deliver

"How do I behave now? Can I sue for the fulfillment of the sales contract? ”Asked the disappointed customer. For this question, the following legal principle should first be pointed out: "Pacta sunt servanda", d. H. the concluded contracts must be fulfilled. The focus here is on "concluded contracts". First of all, if the worst comes to the worst, the question to be answered is whether a binding sales contract has actually been concluded that obliges delivery. To do this, you have to distinguish the respective sales channel:

Online shop

There is no one-size-fits-all answer for online shops. Here, the conclusion of the contract depends on the respective individual regulations in the terms and conditions and customer information. If instant payment methods such as PayPal are used, a binding purchase contract is concluded when the order process is concluded.


Ebay providers post binding offers according to the official platform conditions. In the case of fixed-price items, the buyer accepts the offer by clicking the "Buy It Now" button and then confirming. In the case of fixed-price items for which the seller has selected the "immediate payment" option, the buyer accepts the offer by clicking the "Buy It Now" button and completing the immediately following payment process. The buyer can also accept offers for several articles by placing the articles in the shopping cart and completing the immediately following payment process. At auctions, the buyer accepts the offer by submitting a bid. The acceptance takes place under the condition precedent that the buyer is the highest bidder after the end of the offer period.


In the case of an order via Amazon, the contract is concluded as follows: The order or order confirmation of the customer does not constitute a purchase contract, as the offers are non-binding. By clicking the “Buy now”, “Buy now with 1-Click®” or “Buy with 1-Click®” button, the customer submits a binding offer to the provider. After submitting his order, the customer receives an automatic email confirmation from Amazon that the provider has received the offer. The order confirmation does not yet lead to the conclusion of a contract between the provider and the customer. The acceptance of the offer (and thus the conclusion of the contract) takes place only through an e-mail from Amazon, in which the customer is confirmed that the goods have been dispatched by the provider. Only now is there no turning back.

Command back: cancel a sales contract

However, there are ways and means to get out of the contract. Fortunately, legislators and courts have the subject of “contestation” on their radar. Online retailers who inadvertently offered products at an incorrect price can exercise a right of avoidance if they were in error and did not want to offer the product at that price at all. It does not matter whether the price was entered incorrectly (e.g. by typing it incorrectly) or whether the incorrect price was caused by a software error (e.g. in the merchandise management system or a pricing tool).

The Federal Court of Justice has already ruled that an online retailer in the event of an erroneously incorrect purchase price display in the online shop, which can be traced back to a transmission error, can contest a purchase contract that has already been concluded because of an error (judgment of January 26, 2005, file number VIII ZR 79/04).

The following case does not entitle the holder to contest: The retailer must subsequently adjust the price because, for example, the price of the product has increased. However, this is more common in the travel sector when the cost of flights has increased. One speaks here of a so-called calculation error, which is the responsibility of the retailer.

However, dealers can only invoke the right of avoidance if they actually assert the avoidance and declare to the customer that they no longer want to be bound by the contract. According to the courts, the note "Due to a system malfunction we are unable to process your online order and we are canceling this order" should be sufficient (Higher Regional Court of Düsseldorf, judgment of May 19, 2016, file number I-16 U 72/15). The prerequisite is that the dealer clearly indicates that he wants to withdraw from the contract. The word “challenge” need not be used. A specific form is not required for the declaration of avoidance, but it should be made in writing for reasons of evidence. The affected retailer must also declare the contestation of the contract "immediately" after becoming aware of the incorrect price labeling.

As a result of an effective contestation, the purchase contract is dissolved and is deemed to be void from the start. However, online retailers should be aware that there may be claims for damages.

Taking advantage of a mistake is a violation of good faith

The gleeful customer can still be refused the delivery of the goods at a bargain price for another reason: If the customer insisted on delivery, he would violate the principle of good faith. This is particularly the case with obvious discrepancies between published and actually wanted prices or when comparable offers are significantly more expensive.

However, many customers do not want to hear this and are angry about the cancellation emails. In doing so, they forget that they are consciously exploiting a mistake made by the dealer and that they are by no means right. The case law offers them no backing: The insistence on a low price (for example 29.90 euros instead of 2,990.00 euros) is unfair and illegal (see Dortmund District Court, judgment of February 21, 2017, file number 425 C 9322/16) . The dealer is not obliged to deliver the goods because of the customer's violation of the principle of good faith.

It is abusive if the buyer recognizes the incorrect price indication and the execution of the contract is simply unreasonable for the retailer due to the far too low price. The deliberate exploitation of an obviously erroneous price information in an online booking system can be an abuse of law (see Higher Regional Court Munich, order of November 15, 2002, file number 19 W 2631/02).

Second attempt: Are retailers allowed to insist on a new, higher price?

In some cases the cancellation e-mail contains the information that the customer may not have the goods at the original ridiculous price, but at the regular price or at a low price as a goodwill gesture. From a purely legal point of view, however, the dealer makes the customer a new offer. The customer does not have to accept this. Even if he no longer reacts, the customer has not entered into a new contract.

Danger recognized - danger averted?

Due to the technical possibilities available to them, online retailers are expected to correct errors in the price display within the shortest possible time. Nevertheless, many online retailers rely on information such as "Errors, misprints and price changes reserved" to get rid of errors that have crept in. Such or similar formulations should be avoided in online trading, as they harbor the risk of a warning.

Conclusion and practical tip

As our example mentioned above shows, if there are price errors, customers usually strike several times and buy the stock until it is exhausted. This can result in damage of several thousand euros for the retailer. Once customers smell the big booty, they won't give up on their own that quickly anyway. Here traders have a right of avoidance.

Customers who purposely buy an incorrectly labeled article and who have already recognized and exploited this when placing the order are also acting in an abusive manner if they then insist on a delivery at a low price. You must not invoke the low price.

Without legal help, the cases usually escalate very quickly, especially if the reputation is at stake due to (threatened) negative reviews. The further procedure is therefore on the one hand legal and on the other hand tactical in nature.