Consider the following context:
Person A is moving to the US in July of 2022, formerly not tax-liable in the US (non-reisdent alien). They start a regular employment in the US for the remainder of the year, holding a valid immigration visa, and are now considering the US tax return with the IRS.
I am fairly sure that it is not possible to deduct the full amount for the standard deduction on the tax return, if one moves to the US throughout the year as a former non-resident alien.
According to my own investigations, the IRS itself lists various exemptions on who can claim the full deductions, where the two following scenarios are primarily relevant for the given situation:
[Not Eligible for the Standard Deduction are:] [...]
2. An individual who was a nonresident alien or dual status alien during the year (see below for certain exceptions)
3. An individual who files a return for a period of less than 12 months due to a change in his or her annual accounting period
However, I am unsure whether (3.) is relevant here, as I could not find any clear information on the referenced "change in his or her annual accounting period" expression. Is this a concept mainly relevant for businesses, or is it something that can be applied to regular W-2 incomes of individuals as well?
Mainly, however, I am interested in how the standard deduction will instead be available: Is there a "pro rata temporis" regulation, i.e., allowing a fractional amount of the standard deduction by number of months/days instead? Or is the deduction forfeited completely?