
Colorado HB26-1289: Worldwide Combined Reporting Becomes the C Corp Default in 2027
Starting with tax years beginning January 1, 2027, Colorado's HB26-1289 makes worldwide combined reporting the default for unitary C corporation groups — foreign subsidiaries included. The water's-edge election that avoids it binds for ten consecutive years, and a tax-haven blacklist (Hong Kong, Ireland, the Netherlands, Singapore) pulls listed entities back in regardless. Here's who is affected and what records you need.










