A new Web site provides a state-by-state guide to tax laws and regulations for LGBT couples.

The Online LGBT Tax Resource, at LGBTBar.org/tax, aims to provide a resource for LGBT couples in the wake of the Supreme Court’s landmark decision last year in U.S. v. Windsor.

Tax law remains one of the most complex and nuanced issues affecting the LGBT community, especially in states where couples are not allowed to file married tax returns. Following the Supreme Court’s decision invalidating the federal Defense of Marriage Act, same-sex couples are now eligible to file married federal returns. In 33 states, however, those same couples cannot file joint state returns.

“In states that don’t recognize same-sex marriage, same-sex couples and their tax preparers are struggling to make sense of how to apply the federal tax guidelines based on the ruling last year that the DOMA was unconstitutional,” said John Lillis, a tax partner with White & Case, who worked on the database project pro bono. “This database is an important tool to help tax preparers and same-sex couples navigate the inconsistent rule that applies to state income tax laws.”

The site provides a recap of states’ rules concerning same-sex marriage and the impact on state income tax in clear and concise language, along with individual state guidance for married same-sex taxpayers. In addition, the site offers information on litigation and legislation that could have an impact on LGBT tax law. It also includes up-to-date information from states’ departments of revenue, and state constitutions.

The Online LGBT Tax Resource was developed by the National LGBT Bar Association in conjunction with White & Case on a pro bono basis and BNY Mellon.