DIES, Chief Justice.
On July 6, 1977, Dave Summers Realtors, Inc., and Dave E. Summers, Individually, defendants, executed a lease contract with plaintiff, Astro Leasing, Inc., whereby plaintiff contracted to lease to defendants eight mobile telephones. Plaintiff brought suit in Travis County alleging defendants had failed to make payments after February 20, 1978, and defendants filed a plea of privilege to be sued in Harris County, Texas, which was overruled by the trial court, and from which defendants perfect this appeal.
It is undisputed the contract involved expressly provided that payments were to be made at plaintiff's place of business in Austin, Travis County.
Defendants urge three points of error, but they all contend the contract was modified by plaintiff assigning the contract to a Houston bank, which subsequently notified defendants to send the payments to that bank in Houston.
The contract between the parties contained this sentence: "All waivers under this lease must be in writing."
Tex.Bus. Com Code Ann. § 2.209(b) (1968) provides:
"(b) A signed agreement which excludes modification or rescission except by a signed writing cannot be otherwise modified or rescinded . . . ."
A waiver of the requirement to make payment in Travis County is a modification, which plaintiffs did not authorize in writing. See City of Perryton v. High Plains Natural Gas Company, 413 S.W.2d 740, 741 (Tex.Civ.App. Fort Worth 1967, no writ).
"For venue purposes reference to matters outside the written provisions of contract(s) of the parties could not operate to alter or inhibit the venue rights conferred by the subdivision. (Citing authorities)."
All of defendants' points of error are overruled, and the order of the trial court is affirmed.
AFFIRMED.
CLAYTON, J., not participating.