The "Deadline for submitting a P46 (Car)" is the final date by which individuals or employers in the United Kingdom must submit the P46 (Car) form to HM Revenue and Customs (HMRC). The P46 (Car) form is used to report changes or updates related to company-provided cars and their associated tax implications. This includes situations such as when an employee starts using a company car, changes their car, or stops using a company car. Timely submission of the P46 (Car) form ensures compliance with HMRC regulations and helps ensure accurate tax calculations for both employers and employees. It is important to note that the specific deadline for submitting the P46 (Car) form may vary, so individuals and employers should consult the latest HMRC guidelines or official resources to determine the exact date for a particular tax year or reporting period.