otherwise due

Hi,

I can't understand the 'otherwise due' part of below sentence.

"a reduction of an amount otherwise due; especially : TAX CREDIT "


Could you dumb it down for me?

I'll really appreciate it.

one reason is sth,the other is TAX CREDIT

"amount otherwise due" = the amount before the reduction.

The word 'otherwise' in this context can be substituted with the following and mean the same thing:

"a reduction of an amount that would normally be due;"
"a reduction of an amount that would usually be due;"

Hope this helps.