After sleeping on it, I realized I gave you some incorrect information ( I should know better than to answer questions that late at night) ...
The unused PERSONAL part of the credit would be lost, but the BUSINESS part of the credit would be carried BACK to last year (so you would need to amend the previous year's tax return).
As I said before, it would show up as two credits of $3750 each. Now let's say that Line 47 is only $3000. In that situation, you would be allowed $3000 of your personal credit, and the other $750 of your personal credit would be lost. Your entire business credit of $3750 would be carried back to last year.
