You can apply for additional leave of 12 months. This will allow your Start-up visa to go beyond the normal maximum 2-year period so you can continue developing your business against your agreed business plan. You must meet the requirements of the route as normal, including being endorsed by an endorsing body. Your endorsing body must assess your business and be satisfied that reasonable progress has been made, taking into consideration the impact of coronavirus and that the business remains viable. Your endorsing body must provide you with an endorsement letter. This must state it is an application for a temporary extension by completing the relevant sections and providing the required information, within the endorsement letter.