In 2023, Charlotte's most favorable filing status would be "Head of Household."
To qualify for this status, she must meet the following criteria:
- Unmarried Status: Charlotte is unmarried.
- Dependent: She has a qualifying relative dependent, which is her father, Arlo. Although he did not live with her, the fact that she provides more than half of his maintenance costs meets the requirement.
- Home Maintenance: Charlotte pays for more than half the costs of maintaining a home for herself and her father, which means she can claim him as a dependent.
Being able to file as Head of Household allows her to take advantage of a higher standard deduction and potentially lower tax rates compared to the single filing status. Therefore, Charlotte should file as Head of Household for the 2023 tax year.