Proof of damages for default judgment purposes: proving up liquidated vs. unliquidated damages

WHAT IS CONSIDERED ESTABLISHED WITHOUT A NEED FOR PROOF IN THE DEFAULT JUDGMENT CONTEXT?

In a no-answer default judgment, the failure to file an answer operates as an admission of the material facts alleged in the petition, except as to unliquidated damages. Holt Atherton Indus., Inc. v. Heine, 835 S.W.2d 80, 83 (Tex. 1992).
 
A claim for damages is liquidated if the amount of damages can accurately be calculated by the court from the factual, as opposed to the conclusory allegations in the petition and written instruments. Argyle Mech., Inc. v. Unigus Steel, Inc., 156 S.W.3d 685, 687 (Tex. App.-Dallas 2005, no pet.); see also Novosad v. Cunningham, 38 S.W.3d 767, 773 (Tex. App.-Houston [14th Dist.] 2001, no pet.) (suit to recover amount due for professional services was liquidated claim proved by written instruments where plaintiff attached original instruments to verified petition and motion for default judgment).
 
When damages are unliquidated, the judge must “hear” evidence on the damages. See Argyle Mech., Inc., 156 S.W.3d at 687; see also Tex. R. Civ. P. 243. In contrast, “if the claim is liquidated and proved by an instrument in writing, the damages shall be assessed by the court, or under its direction, and final judgment shall be rendered therefor . . . .” Tex. R. Civ. P. 241.
 
SOURCE: DALLAS COURT OF APPEALS - 05-07-01449-CV (credit card debt suit)