Yes, for any contribution (especially monetary), you have to net out any consideration you received in return for the contribution.
Are you asking if you should carry over the excess contribution in 2019 to 2020? No, each year stands alone. Any year in which you receive consideration that is valued at more than what you contributed, then there is no deduction that year. And for any year in which you contributed more than what you received in consideration, then you can report the net amount.
Or are you saying that you contributed $24 in 2020 but did not receive anything in return in 2020? In this case, it doesn't matter what happened in 2019. Each year is on its own.
Make sense?
If I understand you correctly, you contributed $24 to a qualified charity in 2020, and, in return, they provided you items of value worth $20.
In this case, you enter a charitable contribution of "Money" of $4. That is, you report the next between what you gave and what you got back.
Or are you saying that you donated the money in one year and got the tickets in another year?
Yes, it was difficult to explain in the character limit of the question.
In 2019, I contributed less than I received in a quid-pro-quo. That's not the issue. I was wondering if I still need to subtract the excess received value from additional contribution made in 2020.
Yes, for any contribution (especially monetary), you have to net out any consideration you received in return for the contribution.
Are you asking if you should carry over the excess contribution in 2019 to 2020? No, each year stands alone. Any year in which you receive consideration that is valued at more than what you contributed, then there is no deduction that year. And for any year in which you contributed more than what you received in consideration, then you can report the net amount.
Or are you saying that you contributed $24 in 2020 but did not receive anything in return in 2020? In this case, it doesn't matter what happened in 2019. Each year is on its own.
Make sense?