Allen Iverson -- Dodges Jail Time ... Forks Over $40,000 to Ex

Wanna get Allen Iverson to pay his child support bill? Threaten jail ... because the ex-NBA star finally coughed up the $40,000 he owed his ex wife ... narrowly escaping time in the slammer.

TMZ broke the story ... Iverson's ex, Tawanna, has been trying to collect child support from the b-baller since their divorce was finalized in February, but no cigar. Then, last month she asked a judge to throw him in jail, if he continued to dodge the bill: $8,000 / month for the last 5 months.

In new court docs -- filed last month in Fulton County, GA -- Iverson said he never paid the money because he was led to believe he and Tawanna would reconcile.

Taking a hard stance a judge ordered Iverson pony up the cash within 72 hours ... or be arrested.

The threat apparently worked, Iverson's lawyer tells TMZ ... "Allen has complied with the order and met every term for which he was required."