When you file a joint return, you list all of the combined income and deductions of the married couple. There is one tax refund, although you can direct that it be split to two different bank accounts.
filing jointly usually results in a larger overall refund because many deductions and credits are disallowed or reduced when filing separately. You could prepare separate returns and a joint return and see how you do. Or, an experienced a tax preparer could give you an estimate of what part of a joint refund belongs to each spouse. If you do file jointly, you should certainly agree in advance on how to split the refund. Not every divorcing couple will get along well enough to make joint filing practical, even if it saves money.
