Why would claiming a child dependent increase the amount of tax I owe, I thought claiming a child was a credit, my amount due to federal increased from $450 to $1950?

It should not unless you have kiddie tax or some other unusual thing. Take a look at your tax forms before and after and compare to see which forms/lines changed. Once we know which numbers are affected, we can work things out with refundable and nonrefundable credits and whatever you find. Let us know what forms and lines have changed.

Unfortunately I did not print off the 1st version, I received a rejection letter as it had flagged my dependents, I had a birthdate built in wrong, once I corrected it, it approved as a dependent, I think I figured it out, the incorrect Birthday had put my child under 17, the correct birthdate put her at 17, which reduces the amount of credit by 1500, so i believe that is the difference, thanks for your help