I did not receive the full EIP amounts for EIP 1 and EIP 2 based on my 2019 income, but since my income in 2020 was lower, I could correct this through my 2020 return, having the remainder included in my refund.
Yesterday, I received the EIP 2021 money (the $1400 one), but also only part of it. This happened during the time between my filing my 2020 return and having that return approved.
How do I claim the remainder of the EIP 2021 money? File an amended return? If so, should I do that right away or wait until my return (as submitted) has been approved? Or is there another (simpler) mechanism?