on-line portal which allows taxpayers to— (A) subject to such restrictions as the Secretary may provide, elect to begin or cease receiving payments under this section, (B) provide information to the Secretary which is relevant in determining the monthly advance young adult payment and the taxpayer’s eligibility for such payment, including changes in expected dependent status for the following tax year, and (C) subject to such restrictions as the Secretary may provide, elect to begin or cease an annual lump sum in lieu of monthly payments. (2) Availability in multiple languages The Secretary shall ensure that the on-line portal described in paragraph (1) is available in multiple languages. (3) Administration The Secretary shall identify and allocate the resources necessary to administer the on-line portal described in paragraph (1) and will create an internal review process to ensure the portal is frequently updated for efficiency, accuracy, and ease-of-use. (4) Mobile device compatibility The on-line portal described in paragraph (1) shall be compatible with mobile devices. (5) Determination of dependent status for purposes of advance payment (A) In general For purposes of determining the recipient of any monthly advance young adult payment under this section, a specified young adult shall be treated as a dependent of a taxpayer if such young adult was claimed as a dependent of the taxpayer on the return of tax filed by such taxpayer for the reference year. (B) Reference year The term reference year means, with respect to any taxpayer for any calendar year, the most recent of— (i) in the case of a taxpayer who filed a return of tax for the last taxable year ending before the taxable year in which a payment is made, such taxable year, or (ii) in the case of a taxpayer who filed a return of tax for the taxable year preceding the taxable year described in subparagraph (A), such preceding taxable year. (C) Resolution of multiple claims relating to same dependent In the case of multiple returns of tax claiming a