My son has a business (registered in his home state) providing services for the movie industry. He is an independent contractor, hired on a project (per-movie) basis, and most often has multiple clients at one time. He has occasional travel to meet with clients and perform other business-related tasks. But the question is this: One of his clients required him to be on the job in California for a few months. He traveled out there to be on-site, living in temporary quarters. His company is located in his home state (not California). Many questions: What expenses are deductible as business expenses? Travel to/from California? Meals? Temporary housing? Also, how are state taxes computed? Will both California and the home state require taxes? He also traveled back to his home once during that time (for Christmas). Any deductions there? This whole thing might also be complicated by the fact that he vacated his apartment here to go to the project in California. Will that make it look like he relocated to California?

Time for him to get a real accountant, I guess.