California sets the national high-water mark through Labor Code §2802, which obligates employers to reimburse all necessary business expenses, a phrase courts construe broadly. The leading case, Cochran v. Schwan's Home Service, held that an employer must pay a reasonable percentage of an employee's personal cell phone bill used for work, even when the employee had an unlimited plan and paid nothing extra. California also bars waivers: an employee cannot sign away the §2802 right, so a policy that tries to shift costs onto staff is void. Penalties include the unpaid amounts, interest, and attorney's fees, which is why California reimbursement disputes so often escalate.
Illinois enacted 820 ILCS 115/9.5 in 2019, requiring reimbursement of necessary expenditures within the scope of employment, subject to a written expense policy. The statute is employer-friendlier than California's in one respect: a compliant written policy can set reasonable limits, and an employer is not liable for amounts that exceed those limits or that an employee fails to submit within the policy deadline. That single feature makes a documented policy not just advisable but legally protective in Illinois.
New York has no statewide reimbursement mandate comparable to §2802, so the FLSA kickback rule governs the floor, but New York Labor Law §198-c treats promised expense reimbursements as a form of wage supplement, meaning a failure to pay what the policy promised can become a wage claim. The practical lesson is that in New York your written policy effectively defines your own obligation, so loose drafting creates liability you could have avoided.
Texas imposes no specific reimbursement statute beyond the federal floor, leaving employers free to set terms by contract or policy. That freedom is a double-edged sword: without a clear written policy, disputes default to whatever was promised verbally, and the Texas Payday Law can be invoked to enforce an agreed-upon reimbursement as unpaid wages. Even in a low-regulation state, the document is what protects you.