Short answer. No. Article 78 of the Revised Penal Code is absolute: no penalty shall be executed except by virtue of a final judgment. A conviction that is still under appeal has not become final, and the sentence cannot begin to run until all appeals are resolved or the period to appeal has lapsed.
What the law says
No penalty shall be executed except by virtue of a final judgment.
Revised Penal Code, Article 78 — How A Penalty Is Executed. Read the full provision →
The finality requirement under Article 78
Article 78 of the Revised Penal Code lays down the basic rule on when a sentence may be carried out. It begins without qualification: no penalty shall be executed except by virtue of a final judgment. Finality of judgment is not a procedural technicality — it is the constitutional precondition for punishment. Until the conviction can no longer be reviewed or reversed, the accused retains a legal status distinct from a person already condemned to serve a sentence. The appeal process exists precisely because errors happen; imposing the penalty before that process is complete would be irreversible if the conviction were later overturned.
Serving a sentence only in the form the law prescribes
Article 78 adds a second requirement beyond finality: a penalty shall not be executed in any other form than that prescribed by law, nor with any other circumstances or incidents than those expressly authorized thereby. This means that even after a judgment becomes final, the manner of execution must comply with the statute. A sentence of imprisonment must be served in a facility that follows the conditions the law sets. The convict's diet, work, relationships with others in the facility, the receipt of assistance, and the separation of sexes in institutions are all subject to the regulations Article 78 requires.
Detention before finality is not the same as serving the sentence
A person may be held in detention while a case is pending — either because bail was denied, not applied for, or revoked. That pre-sentence detention is not the same as serving the penalty. If the accused is eventually convicted and the judgment becomes final, the time already spent in preventive detention is generally credited toward the sentence under separate provisions of law. But the service of the penalty itself does not begin until the judgment is final; what comes before is custodial detention, not punishment.
Correction and reform as objectives
Article 78 is not limited to timing and form. It also contemplates that the regulations governing penal institutions shall make provision for the correction and reform of the convicts. This reflects the Revised Penal Code's recognition that imprisonment serves purposes beyond punishment — rehabilitation is also a stated goal. The specific regulations for each type of institution flesh out what correction and reform look like in practice, but Article 78 establishes that these objectives are built into the framework from the statute level.