SALT LAKE CITY—The Salt Lake City Council approved a citywide partner registry Feb. 5, giving same-sex and other domestic partners the opportunity to share insurance benefits.

The voluntary registry is a way for employers who offer benefits to unmarried couples to verify a worker actually has a domestic relationship.

The registry passed on a unanimous vote. Council members say it’s a natural extension of a partner registry they established last year for city workers.

But the registry, praised by gay-rights activists, faces an uncertain future. Conservative Utah state Sen. Chris Buttars (R-West Jordan) has introduced legislation to kill any such government registry.

City officials say the registry doesn’t run afoul of Utah’s constitutional ban on same-sex marriage. Instead, it simply recognizes that families do not always come in the same package, Council Chairwoman Jill Remington Love said.