in Re James David Henry, 04-15-00606-CV

James David Henry established parentage of his son B.A.H. in 2011; conservatorship initially not addressed.
In April 2012 the trial court ordered medical/psych exams of mother Stephanie Markell, appointed Henry temporary sole managing conservator, and placed the child in Henry’s custody; Henry exercised custody in Midland County thereafter.
Henry’s amended petition was dismissed for want of prosecution in December 2014; no permanent custody order was entered before 2015.
In August 2015 Markell took B.A.H. from a hotel parking lot in the Dallas area and brought him to Bexar County; Henry filed a petition to modify conservatorship in Bexar County on September 4, 2015 and moved to transfer venue to Midland County.
Markell opposed transfer, arguing the child now lived in Bexar County and had been "illegally residing with his father" before August 2015; she filed a sworn counter-motion the day of the hearing but did not file a controverting affidavit under the Family Code.
The trial court denied Henry’s motion to transfer on September 21, 2015; Henry petitioned this court for mandamus relief, arguing the court had a mandatory duty to transfer under Tex. Fam. Code § 155.201(b).

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether trial court must transfer modification suit to county where child lived ≥6 months	Henry: mandatory transfer to Midland because child resided there continuously from Apr 2012–Aug 2015	Markell: child now resides in Bexar; prior residence with Henry was "illegal," so transfer improper	Transfer required; trial court abused discretion by denying transfer
Whether opposing party must file controverting affidavit to prevent mandatory transfer	Henry: no controverting affidavit was filed; factual showing of 6-month residence was uncontroverted	Markell: filed sworn counter-motion denying grounds for transfer at hearing (but not §155.204(d) affidavit)	Counter-motion insufficient; lack of controverting affidavit means transfer should have been granted
Whether Henry’s earlier possession waived venue rights due to alleged "illegal" removal	Henry: possession followed a temporary court order making him temporary sole managing conservator; not illegal	Markell: Henry’s possession was illegal and thus he waived right to transfer	Court: Henry’s possession was pursuant to a valid temporary order (and he had conservator authority); waiver not shown
Whether remedy by appeal is adequate such that mandamus is improper	Henry: mandamus appropriate because mandatory venue statutes are ministerial and appellate remedy inadequate	Markell: (implicit) deny mandamus necessity	Court: Mandamus appropriate to correct ministerial failure to transfer

In re Prudential Ins. Co. of Am., 148 S.W.3d 124 (Tex. 2004) (mandamus standard; abuse of discretion)
Walker v. Packer, 827 S.W.2d 833 (Tex. 1992) (mandamus review when trial court misapplies law)
Proffer v. Yates, 734 S.W.2d 671 (Tex. 1987) (mandamus appropriate to enforce venue rights in family law)
In re Leyva, 333 S.W.3d 315 (Tex. App.—San Antonio 2010) (mandatory transfer under Fam. Code §155.201 in modification suits)
In re Wheeler, 177 S.W.3d 350 (Tex. App.—Houston [1st Dist.] 2005) (trial court lacks discretion once six-month residence established)
Huey v. Huey, 200 S.W.3d 851 (Tex. App.—Dallas 2006) (waiver of transfer when children removed in violation of existing order)