Based on the information provided, it is important to note that I am not a legal expert and the information I provide is for general guidance only. In situations like yours, where there is no employment contract but only a confirmation letter, it becomes essential to understand the applicable employment laws and regulations in your country to determine your rights as an employee. However, in general, employment laws often require a notice period for resignation, which can vary depending on factors such as your length of service and the industry you work in. In some cases, the notice period may be stated in the confirmation letter or agreed upon verbally. If there have been no changes communicated to you regarding the notice period during your employment, it may be reasonable to assume that the notice period mentioned in the confirmation letter still stands. Since your current company does not have an HR department for reference, it would be advisable to seek professional legal advice or consult with a local labor board or employment authority in your country. They can provide you with accurate and up-to-date information regarding your specific situation, including your rights and obligations as an employee and how to proceed with your resignation. Remember, labor laws can vary between countries and even within different regions or states, so seeking professional advice is crucial to ensure you are making informed decisions and protecting your rights. Good luck with your situation, and I hope you find the guidance you need from the appropriate authorities or legal professionals.