Warning letter at work: what employees should know

Warning letters are among the most common sources of conflict at work and often mark the first step toward termination. Many employees underestimate a warning letter or simply do not know how to react. At the same time, wording and content often determine whether the letter will matter in an unfair dismissal case. Our article explains when a warning letter can legally be issued, what rights employees have. And which mistakes you should avoid if you receive such a “love letter”.

Requirements for a valid warning

A warning letter is one of the most common conflict points in an employment relationship. It is also very often the first step toward termination. Therefore, strict requirements have been developed by the labor courts:

General requirements

Formally, it is mainly a tool for the employer to point out a breach of contract to the employee. It usually goes hand in hand with the announcement that the employment relationship may be terminated. Provided, of course, if the behavior is repeated. A warning letter is therefore a formal legal instrument. Its role is to warn the employee and give him a chance to improve before more severe measures, such as termination, are considered.

There are also other forms of criticism from the employer, such as a “reminder” or “reprimand”. These usually do not include a threat of future termination and are therefore less serious than a full warning letter.

Not every warning letter is valid. This is particularly important because in many cases a valid warning is a precondition for a later conduct-related termination. If a warning letter does not meet the legal requirements, it often cannot be used to justify a dismissal.

Requirements in detail

A valid warning letter has the following requirements:

• Precise description of the misconduct (reprimand function): The relevant behavior must be described in detail, including the date of the breach. Vague accusations or general statements are not enough.
• Clear reference to a contractual breach (instruction function): The breach of duty must be clearly identified as a contractual violation. And the employee must be expressly requested to stop this behavior in the future.
• Explicit warning of termination (warning function): The warning letter must clearly state that a repetition of such conduct may lead to termination of the employment relationship.
• Proportionality: The warning must be proportionate to the severity of the misconduct. A minor breach can make the warning and the implied threat of termination unreasonable. However, many minor breaches (like regular lateness) give grounds for a warning.

Whether a warning letter is valid can be hard to judge in individual cases. Often, it is necessary to look closely at the case law of the labor courts to assess a specific warning. If in doubt, employees should seek legal advice to correctly assess the situation and to choose the right response.

Examples: Triggers for a Warning Letter

The employer has the right to issue a warning letter for any breach of contractual duties that the employee can control through their own behavior. These breaches can cover many aspects of the employment relationship. Here are some typical examples from case law:

• Repeated lateness without excuse.
• Mobbing or harassment of colleagues that damages the work environment.
• Deliberately poor performance despite clear expectations.
• Insults directed at customers, colleagues, or supervisors.
• Refusal to carry out agreed work duties without a valid reason.
• Feigning illness in order to avoid work.
• Going on vacation without the employer’s approval.
• Prohibited side activities that are contractually banned or create conflicts of interest.
• Excessive private internet use during working hours.
• Alcohol or drug use that affects performance or safety at work.
• Passing on trade or business secrets without authorization.
• Data protection breaches involving personal data.

In other situations, warning letters are not allowed, for example:

• Warning letters for illness: Absences due to illness may not be the subject of a warning. Health issues are not controllable behaviors and lie outside the employee’s responsibility.
• Non-existent duties: If an employer gives an instruction outside the agreed contractual duties and the employee reasonably refuses, this cannot be the basis for a valid warning.

From the first warning letter onward, it is important to keep all documents. Emails, time sheets, internal messages, and meeting notes. Careful documentation often makes the difference later. For instance, if you need to prove in court how a conflict developed or whether a warning letter was justified.

Form of a warning letter

In principle, a warning letter can be issued orally. In practice, however, employers almost always choose the written form. Because then, they can prove later in court that a warning was given and what it contained.

Even so, an oral warning can be relevant from a legal perspective. If you receive an oral warning, it is sensible to make your own written note of the date, content, and people present, so that you can reconstruct events if the dispute escalates.

Who can issue a warning letter?

A warning letter can be issued by both the employer and the employee.

On the employer side, it is not only the employer personally or the person formally authorized to terminate who can issue a warning letter. Other people with binding authority to issue instructions to the affected employee may also do so, for example a direct supervisor.

Warning letters by employees are extremely rare in practice. However, an employee can issue a warning letter themselves or have it issued by an authorized representative, for example a lawyer.

One example of an exceptional employee warning letter is significant wage arrears. Before an employee resorts to drastic measures such as termination and possibly claims damages.¹, they can use a warning letter as a milder tool to give the employer a final chance to correct their behavior.² This can sometimes prevent a termination and an open legal conflict.

Warning letters in dismissal cases

A warning letter is often a precondition for a valid conduct-related termination. Under the principle of proportionality, termination is only valid if there are no other suitable and less severe means to resolve the contractual disruption in the future. A warning letter is such a milder measure and is therefore regularly required before the employer can dismiss for conduct.

There are only a few exceptions where a warning letter can be skipped:

• No change in behavior can reasonably be expected, even after a warning.
• The breach is so serious, and its unlawfulness so obvious, that it is clear the employer cannot be expected to tolerate it even once, for example in cases of serious criminal conduct at work.

When assessing whether a termination is valid, courts look at how many warning letters have been issued, how serious the breaches were, and how often they occurred. In many unfair dismissal cases, courts give employees good chances if the employer cannot show that valid warnings were issued before the termination.

Example: An employee arrives late for work several times in January 2025. At the beginning of February, she received a warning letter for these delays. In March, the employer issues a conduct-related termination based only on the late arrivals from January. This is not permissible, because the warning has already covered those incidents. The termination can only be based on later breaches.

How employees should react

When an employee receives a warning letter, there are several possible ways to react. You should always keep in mind that, in practice, warning letters often prepare the ground for termination. Technically, you could go through the court process alone. But labor court procedures are complex, and handling them without professional support is usually a high-risk move.

Here are some common options:

• Consult an employment lawyer: If you have legal expenses insurance, a first consultation with an employment lawyer is usually the safest next step. Together, you can review whether the warning letter is valid and decide how to respond in a way that protects your position if a dismissal follows later.
• Consider legal expenses insurance in time: If you do not yet have legal expenses insurance, a warning letter can be a good moment to think about it. As long as no termination has been issued and none is clearly imminent, you can still take out a policy, bearing in mind that there is usually a waiting period of around three months before it covers a later dismissal dispute.
• Draft a counterstatement: If a discussion with your employer does not resolve the issue, you have the right to submit a written counterstatement. This must be added to your personnel file and allows you to set out your own perspective and any exonerating facts, which can be important later in court.
• Considering legal action: If the employer refuses to remove an invalid warning letter from the personnel file, you could consider taking legal action to have it removed. Before making this decision, it is advisable to consult an employment lawyer. Because such proceedings can put extra strain on a working relationship that is already tense.

Here are some other alternatives pathways:

• Let’s just talk: If you still have the nerves for it, you can ask for a chat with your manager or HR. Tell them how you see things, clear up any misunderstandings, and ask them to remove the warning from your file. If there’s a works council or staff council, you can loop them in too – they’re there to back you up and calm things down when warnings get messy.
• Accept the warning letter: If the warning is clearly understandable, serious, and – annoyingly – justified, you can just take it on the chin and move on. Sign it, file it mentally under “whatever”, and carry on. However, and at least if you don’t have the new job already waiting for you. Don’t give them a second round by repeating the same behaviour.

Frequently asked questions (FAQ)

1. Section 628 German Civil Code ↩︎
2. Section 628 German Civil Code ↩︎