Your tax liability will be the same,
but there will be an $800 tax
which basically counts as though you paid $800 more than you really did.
If both you and your husband said "married" on your W-4,
then its possible that both of your employers will take out $800 less.
If this happens you`ll have $1600 less taxes withheld,
but you`ll only get one $800 tax credit.
Its typically better to try to figure your W-4 withholding so that you get a small refund,
because when you over-pay and get a big refund,
you are basically loaning your money to the IRS at 0.0% interest.
if this works well for you as a way of forcing you to save,
then I`m not going to object.
I will say you could get the same effect by setting up automatic transfers to savings,
or by having your employer direct deposit a portion into savings,
and put only the remaining amount in your checking account.