W. Va. Code § 23-4-1b
It is the duty of every employer to report to the commission, the successor to the commission or another private carrier, whichever is applicable, every injury sustained by any person in his or her employ. The report shall be on forms prescribed by the commission or the Insurance Commissioner, whichever is applicable, and shall be made within five days of the employer's receipt of the employee's notice of injury, required by section one-a of this article, or within five days after the employer has been notified by the commission or the Insurance Commissioner, whichever is applicable, that a claim for benefits has been filed on account of such injury, whichever is sooner, and, notwithstanding any other provision of this chapter to the contrary, the five-day period may not be extended by the commission the successor to the commission, or another private carrier, whichever is applicable, but the employer has the right to file a supplemental report at a later date. The employer's report of injury shall include a statement as to whether or not, on the basis of the information available, the employer disputes the compensability of the injury or objects to the payment of temporary total disability benefits in connection with the injury. The statements by the employer shall not prejudice the employer's right thereafter to contest the compensability of the injury, or to object to any subsequent finding or award, in accordance with article five of this chapter; but an employer's failure to make timely report of an injury as required in this section, or statements in the report to the effect that the employer does not dispute the compensability of the injury or object to the payment of temporary total disability benefits for the injury, shall be considered to be a waiver of the employer's right to object to any interim payment of temporary total disability benefits paid by the commission, the successor to the commission, or another private carrier with respect to any period from the date of injury to the date of receipt of any objection made to the interim payments by the employer.
W. Va. Code § 23-4-1b