A job offer letter is a formal written communication from an employer to a candidate confirming the terms of employment. It serves as a bridge between verbal offer and signed employment contract: it gives the candidate the specific terms they need to make a decision, and creates a written record of what was agreed before they start. A well-written offer letter reduces disputes before they begin.
In most jurisdictions, a signed job offer letter creates legal obligations, but the degree of binding force depends on its language and local employment law. In the UK and much of Europe, an unconditional offer that is accepted generally creates a contract of employment, even before a formal contract is signed. In the US, employment is generally at-will (Montana is the main exception) unless the offer letter explicitly states otherwise. Be careful about language that implies job security ("permanent role", "long-term position") unless you intend to be held to it, and check with an employment lawyer in your jurisdiction.
A job offer letter is typically shorter, covers the headline terms, and is used to secure acceptance before the formal contract is prepared. An employment contract is a comprehensive legal document covering all terms of employment: intellectual property, non-compete clauses, disciplinary procedures, and so on. In most cases, the offer letter is signed first, the candidate accepts, and then the full employment contract follows. The offer letter should state that a formal contract will be provided.
Give candidates enough time to make a thoughtful decision: 3 to 7 working days is common. Pushing for same-day or next-day acceptance puts candidates under unnecessary pressure and can damage the relationship before the person has even started. Candidates who need more time to resign from a current role or complete their notice period should be accommodated. Withdrawing an offer because a candidate asked for more time to decide is reputationally damaging and, depending on local law and circumstances, can carry legal risk.
Negotiation after an offer is sent is completely normal and should be handled professionally. If a candidate asks for a higher salary, more remote flexibility, or additional benefits, the worst response is to take the offer off the table. Listen, assess against your compensation bands and flexibility, and respond with either an adjustment or a clear explanation of why the offer is at the limit. Candidates who negotiate often become the most engaged employees; they are taking the role seriously.
In many countries the law sets a deadline, and it often falls within the first days of employment. In the European Union, a 2019 directive requires employers to give the core terms in writing between the first working day and the seventh calendar day: the parties, place of work, job title or description, start date, end date for fixed-term roles, probation, pay and working hours. The remaining terms, such as paid leave, training and the termination procedure, follow within one month. An offer letter can cover many of these points, so check what your country requires and plan the paperwork before the start date. Source: European Parliament and Council of the European Union, Directive (EU) 2019/1152 on Transparent and Predictable Working Conditions (2019).