You may be surprised to learn that most indoor plants do NOT have a dormant period in the winter. Indoor plants are native to tropical regions where temperatures and light are fairy constant throughout the year. Although the hours of daylight available for plants indoors are shorter in winter, the reduction in light slows plant growth only a bit. Because they are non-seasonal, most indoor plants can be pruned and repotted at any time of year.
Here are the names of some common indoor flowering plants that DO have dormant or semi-dormant periods, usually in the fall: Amaryllis (dry), Anthurium (cool), Azalea (cool), Camellia (cool), Christmas Cactus (cold), Gardenia (cool), Gloxinia (dry), Hibiscus (cool and dry), Kalanchoe (short days), Oxalis (dry), and Poinsettia (short days).