As I said in my original reply, complete page 1 of Form 3520 and Part IV on page 6, U.S. Recipients of Gifts or Bequests Received During the Current Tax Year From Foreign Persons. See this link to Form 3520.
https://www.irs.gov/pub/irs-pdf/f3520.pdf
I am not a lawyer. But the fact that your name is on the bank account as a joint owner, I believe you have a reporting requirement. And assuming the account earns interest income, as a joint tenant of the account, I believe you are required to report the interest income in your income tax return as well. Remember, you as a U.S. taxpayer, has the burden to prove that the interest income is not yours. How do you prove that when the bank sends you a 1099-INT with your social security number on it? IRS routinely chooses form over substance, or vice versa, when it's to their advantage. When the IRS audits tax returns, they mostly do it about two years after the filing, so they also have the advantage of hindsight as to what and how the money was used.
Banks used to routinely open accounts for non-resident aliens (NRA). However, due to various U.S. rules and regulations, including FATCA, some banks are now unwilling to open accounts for NRA's. So check with your bank. Not having a social security number should not be a problem per se. You can always help your parents apply for an ITIN, but again, check with the bank and see if they require an ITIN first. See https://www.irs.gov/individuals/how-do-i-apply-for-an-itin
From the IRS Form 3520 instructions:
Part IV—U.S. Recipients of Gifts or Bequests Received During the Current Tax Year From Foreign Persons
Note.
If you fail to timely report foreign gifts that should be reported under section 6039F, the IRS may determine the income tax consequences of the receipt of such gift and penalties may be imposed. See Penalties , earlier.
A gift to a U.S. person does not include any amount paid for qualified tuition or medical payments made on behalf of the U.S. person.
If a foreign trust makes a distribution to a U.S. person, the U.S. person must report the amount as a distribution in Part III, rather than as a gift in Part IV.
Contributions of property by foreign persons to domestic or foreign trusts that have U.S. beneficiaries are not reportable by those beneficiaries in Part IV unless they are treated as receiving the contribution in the year of the transfer (for example, if the U.S. beneficiary is treated as an owner of that portion of the trust under section 678, then the contribution must be reported by such U.S. beneficiary in Part IV).
A domestic trust that is not treated as owned by another person is required to report the receipt of a contribution to the trust from a foreign person as a gift in Part IV.
A domestic trust that is treated as owned by a foreign person is not required to report the receipt of a contribution to the trust from a foreign person. However, a U.S. person should report the receipt of a distribution from a domestic trust that is treated as owned by a foreign person as a gift from a foreign person in Part IV, rather than as a distribution to a U.S. person in Part III.
Line 54.
To calculate the threshold amount ($100,000), you must aggregate gifts from different foreign nonresident aliens and foreign estates if you know (or have reason to know) that those persons are related to each other (see Related Person , earlier) or one is acting as a nominee or intermediary for the other. For example, if you receive a gift of $75,000 from nonresident alien individual A and a gift of $40,000 from nonresident alien individual B, and you know that A and B are related, you must answer “Yes” and complete columns (a) through (c) for each gift.
If you answered “Yes” to the question on line 54 and none of the gifts or bequests received exceeds $5,000, do not complete columns (a) through (c) of line 54. Instead, enter in column (b) of the first line, “No gifts or bequests exceed $5,000.”
Line 55.
Answer “Yes” if you received aggregate amounts in excess of the section 6039F threshold amount during the current tax year that you treated as gifts from foreign corporations or foreign partnerships (or any foreign persons that you know (or have reason to know) are related to such foreign corporations or foreign partnerships). The threshold amount from Rev. Proc. 2021-45 is available at IRS.gov/Newsroom/IRS-Provides-Tax-Inflation-Adjustments-for-Tax-Year-2022.
For example, if you, a calendar-year taxpayer during 2022, received $8,000 from foreign corporation X that you treated as a gift, and $10,000 that you received from nonresident alien A that you treated as a gift, and you know that X is wholly owned by A, you must complete columns (a) through (g) for each gift.
Note.
Gifts from foreign corporations or foreign partnerships are subject to recharacterization by the IRS under section 672(f)(4).
Line 56.
If you answered “Yes” to the question on line 56 and the ultimate donor on whose behalf the reporting donor is acting is a foreign corporation or foreign partnership, attach an explanation including the ultimate foreign donor's name; address; TIN, if any; and status as a corporation or partnership.
If the ultimate donor is a foreign trust, treat the amount received as a distribution from a foreign trust and complete Part III.
