Short answer. A judgment becomes final after the period for perfecting an appeal has lapsed, when the sentence has been partially or totally satisfied or served, when the accused has waived their right to appeal in writing, or when the accused has applied for probation.
What the law says
a judgment becomes final after the lapse of the period for perfecting an appeal, or when the sentence has been partially or totally satisfied or served, or when the accused has waived in writing his right to appeal, or has applied for probation
Rule 120, Section 7 — Modification of judgment. Read the full provision →
Letting the appeal period lapse is the most common trigger
The first and most common way finality arrives is simply the lapse of the period for perfecting an appeal. If the accused does nothing to appeal within the time allowed, the judgment becomes final on its own once that window closes — no further action from either side is needed to make it so, and no separate order declaring finality is required.
This is the default path to finality for a convicted person who simply does not pursue any of the other options available to them.
Satisfying the sentence also finalizes the judgment
Finality can also come from the accused's own conduct after conviction: when the sentence has been partially or totally satisfied or served. Beginning to serve, or fully serving, the sentence is itself treated as an event that finalizes the judgment, separate from whether the appeal period has run its full course.
This reflects the idea that accepting punishment, even in part, is treated as inconsistent with still actively contesting the underlying conviction on appeal.
Waiving the right to appeal, or applying for probation
The remaining two triggers are affirmative choices by the accused: a written waiver of the right to appeal, or an application for probation. Both are treated as the accused's own decision to accept the judgment rather than contest it further, and each independently makes the conviction final, without needing to wait out the ordinary appeal period.
An accused weighing whether to apply for probation should understand that doing so has this finalizing effect on the underlying conviction.
Before finality, the judgment can still be modified
Until one of these events occurs, the judgment is not yet final, and the rule allows it to be modified or set aside before it becomes final or before appeal is perfected, upon motion of the accused. Understanding exactly when finality attaches is what tells an accused person whether that window for seeking modification is still genuinely open or has already closed for good and cannot be reopened.