Le r nf e l d 3 : K a uf v e r t r a g - R e c h t s l a g e u n d L e i s t u n g s s t ö r u n g e n

Legal Capacity and the Capacity to Act

Rechtsfahigkeit, or legal capacity, refers to the status of being a subject of rights. Every human being, defined as a natural person, possesses legal capacity from the moment of birth until the moment of death. This means they are carriers of rights, such as ownership and inheritance, and obligations, such as the duty to pay taxes. For instance, even a baby can legally be the owner of real estate through inheritance. Synonyms for this concept include Rechtsinhaberschaft or Rechtszustandigkeit.

Geschaftsfahigkeit, or the capacity to act, is the ability to independently issue legally effective declarations of will and enter into contracts. This capacity depends on a person's age and mental state and is divided into three distinct stages. The first stage is business incapacity (Geschaftsunfahigkeit), which applies to children aged $0$ to $6$. In this stage, the individual cannot enter into contracts; instead, their parents or legal guardians must act on their behalf. The second stage is limited legal capacity (Beschrankt geschaftsfahig), applying to minors aged $7$ to $17$. Contracts entered by individuals in this stage are often "vulnerably ineffective" (schwebend unwirksam) and require parental consent. An exception is the "Pocket Money Paragraph" ($\S\,110\text{ BGB}$), which allows for valid purchases made with the minor's own funds. The third stage is full legal capacity (Voll geschaftsfahig), which begins at age $18$, allowing for independent and fully effective contracts. Synonyms for this include Handlungsfahigkeit and Vertragsfahigkeit.

Practical examples illustrate these differences: a $5$-year-old child is legally capable of inheriting a fortune but lacks the capacity to buy a mobile phone. A $10$-year-old is legally capable of owning a savings book but is only limitedly capable of acting, meaning they cannot withdraw the money without assistance. A $20$-year-old possesses both legal and acting capacity and can sign an employment contract independently.

The Two-Part Nature of Sales Contracts: Obligation and Fulfillment

A sales contract in German law consists of two separate legal acts: the Verpflichtungsgeschaft (obligatory transaction) and the Erfullungsgeschaft (disposition or fulfillment transaction). The Verpflichtungsgeschaft, also known as the causal transaction, occurs when two matching declarations of will (offer and acceptance) obligate the buyer and seller to perform. At this stage, the goods still legally belong to the seller, but a claim (Anspruch) is established. The seller is obligated to deliver and transfer ownership, while the buyer is obligated to pay the purchase price. Because both parties owe a performance, it is a bilateral obligatory transaction.

The Erfullungsgeschaft, or the fulfillment transaction, is the actual physical transfer and transfer of ownership of the goods, alongside the payment of money. This is the "in rem" act where ownership actually changes hands. While these two acts can happen simultaneously, such as at a supermarket checkout, they are legally distinct according to the principle of abstraction.

Declarations of Will (Willenserklarungen)

A declaration of will is a statement or action intended to bring about a legal consequence. It is the fundamental requirement for the formation of legal transactions like sales or rental agreements. It consists of two elements: the objective fact (the external act of declaring, like a signature or a verbal agreement) and the subjective fact (the inner will, meaning the person must actually intend for a legal effect to occur).

There are several forms of issuing a declaration of will. It can be oral, such as a personal conversation, phone call, or video conference. It can be written, via letter, fax, or a signed document. It can be electronic, such as an e-mail, SMS, or clicking a "buy" button on a web form. It can also occur through conclusive action (konkludentes Handeln), where behavior implies a legal intent, such as nodding, boarding a bus, or scanning goods at a self-service checkout. Silence, however, is generally not considered a declaration of will, except among merchants under $\S\,362\text{ HGB}$, where silence on a business confirmation letter can count as acceptance.

Declarations are further classified by whether they must be received to be effective. Receipt-essential declarations (Empfangsbedurftige Willenserklarungen) must reach the recipient. If between parties present (Unter Anwesenden), they are effective when understood. If between absent parties (Unter Abwesenden), they are effective when they enter the recipient's sphere of control (like a mailbox). Non-receipt-essential declarations (Nicht empfangsbedurftige Willenserklarungen), such as a testament ($\S\,1937\text{ BGB}$) or the abandonment of ownership, are effective immediately upon being made.

Application Examples: Offer and Acceptance

In various scenarios, the distinction between an invitation to offer (invitatio ad offerendum) and a binding offer (Antrag) is crucial. In a restaurant, a menu is not an offer but an invitation to offer. Lisa's order of Pasta Bolognese for $\$12{,}90\,\text{€}$ constitutes the legal offer, and the waiter's notation or bringing of the food represents the acceptance. In a furniture store scenario, a law firm's written order for $5$ chairs at $\$250\,\text{€}$ each is the offer, and the store's confirmation is the acceptance.

Negotiations can involve multiple counter-offers. If a car dealer offers a vehicle for $\$18{,}000\,\text{€}$, and Herr Schmidt offers $\$16{,}500\,\text{€}$, the original offer is rejected and replaced by a new offer. If the dealer then offers $\$17{,}000\,\text{€}$ and Herr Schmidt says "Agreed," the final offer of $\$17{,}000\,\text{€}$ is accepted. In a supermarket, price tags are not binding offers. The offer occurs when Mara places the water bottle on the belt; the acceptance occurs when the cashier scans it and states the price of $\$1{,}000\,\text{€}$.

Nullity and Voidability of Legal Transactions

Legal transactions can be defective, resulting in either Nichtigkeit (nullity) or Anfechtbarkeit (voidability). A null (nichtig) transaction is invalid from the very beginning; it never legally existed. Any performance already rendered must be returned. Reasons for nullity include declarations by those with business incapacity ($\S\,105\text{ BGB}$, children $0$-$6$), declarations made while unconscious or via temporary mental disturbance ($\S\,105\text{ BGB}$, such as severe intoxication), violations of public policy or usury ($\S\,138\text{ BGB}$, such as locksmiths charging $\$5{,}000\,\text{€}$), violation of legal prohibitions ($\S\,134\text{ BGB}$, like weapons or drug trafficking), lack of mandatory legal form ($\S\,125\text{ BGB}$, like selling land without a notary), or sham/prank transactions ($\S\,117, 118\text{ BGB}$).

An avoidable (anfechtbar) transaction is initially valid but becomes retrospectively invalid (ex tunc) once successfully contested. Grounds for avoidance include error under $\S\,119, 120\text{ BGB}$, such as an error in the declaration act (typing or speaking the wrong thing), an error in content (misunderstanding the meaning), an error in essential qualities of a person or object, or a transmission error by a messenger. Other grounds include unlawful threats ($\S\,123\text{ BGB}$, like threatening termination to force an agreement) or fraudulent deception ($\S\,123\text{ BGB}$, like lying about a car's history). In the case of an error, the contestation must happen immediately after knowledge. In cases of deception or threat, it must happen within one year of discovery or the end of the threat.

Case Studies in Nullity and Voidability

In a professional scenario, a law firm mistakenly orders $15$ black desks instead of white ones. This is an avoidable error under $\S\,119\text{ BGB}$. In further examples: a $16$-year-old buying an E-Bike for $\$2{,}500\,\text{€}$ without parental consent creates a "vulnerably ineffective" contract; without consent, it becomes null. An elderly client pressured by a salesperson to sign an overpriced contract can contest it due to unlawful threat ($\S\,123\text{ BGB}$). A client signing a contract for a condominium without notarization finds the contract null due to form violation ($\S\,125\text{ BGB}$). Contracts for illegal work (Schwarzarbeit) are null due to legal violation ($\S\,134\text{ BGB}$).

Defects in Goods (Mangelhafte Lieferung)

A seller is obligated to provide goods free of defects. Defects are divided into Sachmangel (material defects) and Rechtsmangel (legal defects). Material defects include quality defects (the item does not match the agreed quality, such as a scratch in a desk display), assembly defects (wrongful assembly by the seller), a "wrong" delivery (Aliud-Lieferung, such as delivering the wrong model), quantity defects (delivering too much or too little), or defective assembly instructions (the "IKEA clause"). A legal defect ($\S\,435\text{ BGB}$) occurs when third parties have rights to the object, such as a retention of title or when the seller is not the owner.

Defects can be "open" (immediately visible, like a display crack) or "hidden" (detectable only later). For consumers ($\S\,13\text{ BGB}$), a reversal of the burden of proof (Beweislastumkehr) applies for $12$ months under $\S\,477\text{ BGB}$, meaning the seller must prove the defect did not exist at the time of purchase. For entrepreneurs ($\S\,14\text{ BGB}$), like a notary's office purchasing desks, there is a duty to inspect and give notice of defects immediately ($\S\,377\text{ HGB}$, Rugepflicht), or they lose their warranty rights.

Warranties (Gewahrleistung) are legally required for $2$ years. Guarantees (Garantie) are voluntary promises made by manufacturers or dealers. Under the updated $\S\,475\text{b BGB}$, products with digital elements (smartphones, e-bikes) require the seller to provide updates and information about them to maintain functionality.

Buyer's Rights in Defective Deliveries

Rights are divided into primary and secondary categories. The primary right is Nacherfullung (supplementary performance) under $\S\,437\,Nr.\,1, 439\text{ BGB}$. The buyer can choose between Nachbesserung (repair) or Ersatzlieferung (replacement with a new item). The seller generally has two attempts at repair before it is considered failed. If the seller is at fault, the buyer can also seek damages alongside performance.

Secondary rights apply after a reasonable deadline has passed or if supplementary performance failed. These include withdrawal from the contract (Rucktritt, $\S\,323\text{ BGB}$), price reduction (Minderung, $\S\,441\text{ BGB}$), damages instead of performance (Schadensersatz statt der Leistung, $\S\,280, 281\text{ BGB}$), or reimbursement of futile expenses ($\S\,284\text{ BGB}$). For example, if a fake "Hundertwasser" painting is sold as real but is actually damaged, the buyer might choose to keep it but demand a price reduction equal to the value loss.

Late Delivery (Lieferungsverzug)

Deliveries are late when the seller does not deliver on time. Prerequisites for delay include a valid sales contract, a due claim (Falligkeit), and typically a warning (Mahnung) from the buyer. A warning is unnecessary if the delivery time was fixed by the calendar (e.g., "Delivery on August 15, 2020"), if the seller refuses to perform, or if special circumstances justify immediate delay. The seller is not in delay if the cause is beyond their control (Force Majeure).

Without a deadline, the buyer can demand delivery and damages for delay ($\S\,280\text{ BGB}$, covering costs like renting a temporary replacement). After a deadline, the buyer can withdraw ($\S\,323\text{ BGB}$) or demand damages instead of performance ($\S\,281\text{ BGB}$). Special types include Fixed Transactions (Fixkauf), where the delivery must happen at a specific time for the contract to keep its purpose (like catering for a specific event), in which case a deadline is not needed for withdrawal.

Default of Acceptance (Annahmeverzug)

Annahmeverzug occurs when the buyer fails to accept goods that were offered correctly at the right time and place ($\S\,433\,Abs.\,2\text{ BGB}$, $\S\,293\text{ ff. BGB}$). This improves the seller's position: their liability is reduced to intent and gross negligence ($\S\,300\text{ BGB}$), and the risk of accidental destruction (Gefahrubergang) passes to the buyer. If Dr. Schmidt refuses a desk delivery because he found a cheaper one elsewhere, he is in default of acceptance.

The seller's rights include storage of the goods at the buyer's expense and risk ($\S\,304, 372\text{ BGB}$), a lawsuit for acceptance, or a self-help sale (public auction). For perishable goods, a "not-sale" (emergency sale) can occur without prior warning. The buyer must cover any difference between the contract price and a lower auction price.

Questions & Discussion

Question: Is Dr. Schmidt in default of acceptance if he refuses a desk because he found a cheaper one?
Response: Yes, because the seller offered the goods properly according to the contract, and finding a better price later is not a legal justification for refusal.

Question: Must a buyer like Paula allow a repair attempt for a notebook with a quiet sound system?
Response: Yes, supplementary performance (Nacherfullung) is a primary right of the seller; the buyer cannot immediately withdraw from the contract without giving the seller a chance to fix it or replace it.

Question: What happens if a stored item is destroyed by lightning while the buyer is in default of acceptance?
Response: The risk has already passed to the buyer ($\S\,300\,Abs.\,2\text{ BGB}$). The buyer must still pay the full purchase price even though the item is destroyed.

Question: Is a warning letter necessary if the delivery was promised "at the latest by April 1, 2025"?
Response: No, the delay begins automatically on April 2, 2025, because the date was determined by the calendar per $\S\,286\,Abs.\,2\,Nr.\,1\text{ BGB}$.