'Real Housewives of Atlanta' alum Kim Zolciak is no longer at risk of being thrown behind bars ... 'cause she coughed up the money she owed to a court-appointed guardian in her bitter divorce ... TMZ has learned.

According to new legal docs, obtained by TMZ, a Georgia judge ordered Kim to cough up $2,535 in unpaid fees owed to the guardian ad litem assigned in her divorce case with Kroy Biermann.

The judge previously had the guardian interview Kim, Kroy, and their four minor kids to reach a determination on custody issues in the case.

The order said if Kim failed to pay the money by next month ... she might have been incarcerated.

Sources familiar with the situation tell TMZ ... Kim paid the bill in full on Tuesday July, 14.

Kim has had issues with the guardian in the past and claimed she was not taking her claims of abuse and concerns about Kroy's parenting into consideration.

Kroy has claimed the kids were suffering mental abuse at the hands of Kim. He said Kim believes the guardian was out to get her ... which he insists is nonsense.

As you know, Kim and Kroy have been going back and forth in court for years as they fight over custody and support.

Kim's adult daughter, Brielle Biermann, recently revealed she hasn't talked to Kroy in some time … and doesn't think he'll be at her upcoming wedding.