Solange Knowles -- Nailed By Taxman Days After Marriage

8:00 AM PT -- A rep for Solange tells TMZ ... "The lien is in process of being removed as there was simply confusion on whether Solange was a California resident. We expect this to come to a swift close."

While Beyonce shops for $70 million homes, her sister Solange is getting dogged by the taxman almost immediately after she got hitched.

Solange needs to settle up with the State of California, which claims she owes more than $55,000 in taxes for 2010-12.

And to add insult to injury ... the tax lien was filed 3 days after Solange tied the knot.

Meanwhile, back at the homestead, Mathew Knowles is having a marathon garage sale where he's hawking Solange's CDs for $1.96. A Beyonce poster is going for $200.

Life ... it isn't always fair.