California contractors have a solid list of deductible expenses when the books are kept properly throughout the year. The categories below cover most of what trades businesses can write off, plus the California-specific wrinkles that differ from federal rules.

Vehicle expenses for work trucks and service vehicles are deductible. You choose between the standard mileage rate or actual expenses including fuel, insurance, maintenance, registration, and depreciation. For contractors putting heavy mileage on a work truck with frequent repairs, actual expenses usually produces a larger deduction than the standard rate. Either method requires a contemporaneous mileage log showing date, business purpose, and miles driven.

Tools and equipment purchases qualify for Section 179 expensing, which lets you deduct the full cost in the year of purchase instead of depreciating over several years. This is where California parts ways with federal law. Federal Section 179 allows over $1 million in annual expensing. California caps the state deduction at $25,000. If you buy $80,000 of equipment this year, you get the full deduction federally but only $25,000 on your California return. The remainder depreciates over time for state purposes. California also doesn’t conform to federal bonus depreciation at all.

Materials consumed on jobs are fully deductible. Good construction bookkeeping codes materials to the specific job they were used on, which matters for project profitability even though everything deducts at the business level.

Subcontractor payments reduce taxable income fully. Payments of $600 or more to unincorporated subs require 1099-NEC forms filed with the IRS and California by January 31. Missing these filings creates penalties and can put the deduction at risk if audited.

Insurance premiums including general liability, workers compensation, commercial auto, inland marine coverage on tools, and umbrella policies are all deductible. Bond premiums for the CSLB contractor license bond and any job-specific performance or payment bonds are also deductible.

License and permit fees including CSLB license renewals, city business licenses, specialty certifications, and job-specific building permits count as ordinary business expenses.

Safety equipment ranging from hard hats and steel-toe boots to harnesses, respirators, fall protection, and first aid supplies is deductible. PPE you provide to crew members is fully deductible too.

Continuing education that maintains or improves trade skills qualifies. CSLB courses, OSHA training, manufacturer product certifications, industry conferences, and trade association dues are all deductible. Travel costs tied to out-of-town training also count.

Home office applies if you use part of your home regularly and exclusively for business. Contractors who run estimating, scheduling, payroll, and billing from a home office can use the simplified method (5 dollars per square foot, 300 square foot maximum) or actual expenses prorated by the business-use percentage.

Beyond Section 179, California diverges from federal law in other ways that affect contractors. Bonus depreciation isn’t allowed. Certain federal credits have no state equivalent. Some meal deduction rules differ. Your federal return and California return often produce different bottom lines for the same business, which is why contractors get caught off guard by state tax bills when planning only around federal numbers.

Documentation is what makes deductions hold up under scrutiny. Save receipts digitally, track mileage as you drive rather than reconstructing it from memory, and keep license and certification records organized. Missed paperwork is what gets deductions disallowed, not the deductions themselves. Working with bookkeeping services in Pasadena that understand both construction accounting and California tax rules means deductions get tracked correctly year-round, and tax time stops being a scramble.