Texas law requires you to file the death certificate with the local registrar within ten days after the death and before final disposition. (Texas Health & Safety Code § 193.003.)
The deceased person’s doctor, the medical examiner, or a justice of the peace must supply the date, time, and cause of death within five days after receiving the death certificate.
You will need certified copies of the death certificate to carry out certain tasks after the death, such as arranging for the disposition of the body and transferring the deceased person’s property to inheritors.