Letter of Undertaking or LUT is an undertaking filed by an exporter of goods or service which permits him to export goods or services without payment of IGST subject to the condition that he will complete the process of export of goods or services within the prescribed time limit..
According to the Notification No. 37/2017 – Central Tax, it’s mandatory to file LUT for exporting goods or services or both without paying the IGST.
In case, an exporter fails to submit LUT the person needs to pay IGST or has to provide an export bond. Earlier LUT was only available to file offline at the concerned GST office. But now, the Government of India has made the LUT filing process online to ease the process.