Hello Sir,
1. You have to file Income Tax returns every year the due date of which is 31st July.
2. You can very well claim expenses like salary, fuel, maintenance, depreciation etc at the time of filing your returns. If is preferred if you maintain and keep the expense bills and vouchers.
Trust this clarifies your query
Feel free to get back/ call back for any further clarifications.
Thanking You
Regards
ROHIT R SHARMA
BCOM, ACA, LLB - GEN, CERT. FAFP