En Banc. Durham, J. Dore, C.j., Utter, Brachtenbach, Dolliver, Andersen, Smith, and Guy, JJ., and Callow, J. Pro Tem., concur. Johnson, J., did not participate in the disposition of this case.
Jack W. French brought an attorney malpractice action against Sandra Gabriel, Jeff Morris, and Jeff A. Morris, P.S., a professional service corporation (the corporation). The trial court entered judgment for French and awarded damages and prejudgment interest. The Court of Appeals reversed, holding that the trial court lacked personal jurisdiction over the defendants as individuals because service of process was insufficient, that the defense of insufficient service of process had not been waived, and that the trial court erred in holding the corporation liable for torts committed by Morris and Gabriel*fn1 before the corporation was formed. We affirm.
In 1981, French entered into an agreement to sell his beauty school to three investors. The parties contacted Jeff Morris to prepare the legal papers. However, the actual work was done by Morris's associate, Sandra Gabriel. The agreement of sale, which was signed on March 9, 1981, contained no security interest for French in the event of default. At the time the agreement was drafted, Morris was a sole proprietor. He did not incorporate his practice until August 1982.
In March 1983, the investors defaulted on the contract. In September 1984, they filed bankruptcy and French learned for the first time that he was an unsecured creditor.
In January 1986, French filed a malpractice action against Gabriel alleging negligence and a violation of the Consumer Protection Act (CPA), RCW 19.86. The complaint was amended in February to include Morris and the corporation as defendants. Neither Morris nor Gabriel were personally served. The affidavits of service indicate that Gabriel was served by leaving a copy with "[h]er personal secretary" and Morris was served by leaving a copy with "Bobbie, Secretary to Jeff A. Morris".
On February 28, 1986, Morris filed a notice of appearance. On August 15, 1986, he filed an answer in which he raised a number of affirmative defenses, including insufficient service of process. On August 26, 1986, French noted the case for trial and requested a November trial date. Morris objected to setting a trial date because the parties had not yet commenced discovery. The trial date was stricken and the case continued. On June 9, 1987, French filed a second amended complaint. Morris answered the second amended complaint on July 9, 1987, and continued to raise the affirmative defenses, including insufficient service of process. French made no attempt to serve Morris again.
In October 1987, French moved for partial summary judgment on the issues of liability and his claim under the CPA. In his memorandum in opposition to French's motion for summary judgment, Morris asserted that the CPA did not apply to French's claim and, even if it did, issues of material fact precluded summary judgment in favor of French. To the contrary, Morris asserted that summary judgment in his favor was appropriate. The court denied French's motion and dismissed the CPA claim, concluding that it had "no application to the allegations made in [French's] complaint." The case then proceeded to trial.
After French's opening statement, Morris moved to dismiss the claims against him individually for insufficient
service of process. He renewed his motion at the conclusion of the trial. The court denied both motions on the basis that Morris had waived this defense. At the close of trial, Morris also moved for dismissal of the claims against the corporation. The motion was denied.
The court found that Morris had breached his duty owed to French by failing to create a security interest in the sales agreement. French was awarded damages plus prejudgment interest accruing from September 1984, the date that he first learned that he was not a secured creditor in the sale.
The Court of Appeals reversed, holding that the claims against Morris and Gabriel individually should have been dismissed because proper service was not made upon them and they had not waived the defense of insufficient service of process. The court also held that the trial court erred in holding the corporation liable for the preincorporation acts of Morris and Gabriel. French v. Gabriel, 57 Wash. App. 217, 788 P.2d 569 (1990).*fn2
Because French does not seek review of the Court of Appeals' holding that service on Morris and Gabriel was insufficient, the issue of waiver is determinative as to the claims against them individually. French makes a number of arguments in support of his contention that Morris waived the defense. First, he argues that the defense was waived under CR 12 because Morris failed to include it in a responsive motion. Next, he argues that Morris's 6-month delay in filing his answer was dilatory conduct supporting a common law waiver. Finally, he argues that Morris is estopped from asserting the defense. We deal with each of these arguments in turn.
 The defense of insufficient service of process is waived unless the party asserts it either in a responsive pleading or in a motion ...