What the statute actually requires
Section 716.054 of the Texas Health and Safety Code sets the waiting period. A crematory establishment may not cremate remains before 48 hours have passed since death, and the clock runs from the time of death recorded on the certification, not from the moment the family made contact.
A waiver is possible through the medical examiner or a justice of the peace. It is not a formality and it is not something a provider can arrange for convenience.
Why the rule exists
Burial is reversible in the sense that a body can be exhumed. Cremation is not. Once it has happened, any question about cause of death that later occurs to a physician, an insurer or a family member can no longer be answered by examination. The waiting period is a deliberate pause that keeps that door open for two days.
It is the same reasoning that puts a medical examiner between an unattended death and a crematory.
What it means in practice
In practice the 48 hours rarely lengthens anything, because the paperwork usually takes at least that long anyway. The certifying physician has to sign, and the county has to issue the permit. Families who feel the wait most acutely are those where everything else moved quickly — a hospice death with a physician immediately available, for instance.
It also means someone has to hold the body properly for at least two days, which is why refrigeration is a real cost and worth asking whether it is included.
What it does not mean
It does not mean a service has to be delayed — a memorial can be held whenever the family wishes, before or after. It does not mean the ashes take 48 hours; they take longer. And it does not vary by provider, so it is not something to shop around for.