The antonyms for the term "close one's doors" are varied and many. The opposite of shutting down one's operations or stopping the functioning of a business, organization, or company could be opening up, starting, or expanding. Instead of closing the doors, one could choose to launch a new initiative, project, or venture. Another antonym could be remaining active, continuing operations, or staying open for business. Additionally, one could choose to strengthen or enhance its services, products, or offerings, rather than shutting them down. Overall, the antonyms for close one's doors are related to growth and expansion, rather than contraction or reduction.