As the saying goes, there’s nothing certain in life except for death and taxes. But when it comes to selling your home, proactive tax planning can help you reduce your federal income tax bill.

A Costly Mistake to Avoid

Let’s say Tom is a soon-to-be married homeowner who’s looking to sell his principal residence. If certain tests are met, an unmarried individual may be able to exclude up to $250,000 of taxable gain.

Just before the wedding, Tom sells the home he’d purchased 20 years earlier. The home had appreciated by $500,000. He and his future wife, Stacy, plan to move into her much smaller fixer-upper home after the wedding.

As an unmarried taxpayer, Tom can exclude $250,000 of the gain from the sale of his home, leaving a taxable gain of $250,000 ($500,000 minus the $250,000 federal home sale gain exclusion). He owes 15% federal income tax on the gain, plus the 3.8% net investment income tax and state income tax.

Instead, suppose that Tom and Stacy had taken the time to seek tax planning advice. Their tax advisor would have let them know that the home sale gain exclusion for married couples is $500,000 if various tests are met, including that both spouses have resided in the home as their principal residence for at least two years.

Rather than sell Tom’s house before the wedding, they might have kept it and lived in it as a married couple for two years. That would have allowed them to avoid the full $500,000 in taxable gain and the resulting taxes when they later sold it. Even if Stacy had sold her fixer-upper home before the wedding, the gain would likely have been much smaller and may have been fully sheltered with her $250,000 home sale gain exclusion.