Does probation automatically terminate once the probation period ends?

No. Unfortunately, a probationer continues to be on probation until the issuance of an order of final discharge by the court.

This was the ruling in Bala vs. Hon. Martinez, et al., G.R. No. 67301, 29 January 1990, where the Supreme Court explained that only an order of final discharge by the court may operate to restore a probationer's suspended civil rights. Hence, as long as no final discharge is issued by the court which granted the probation, the probation may be revoked and the probationer may be ordered committed to serve his original sentence. Probation is not co-terminus with its period.

Therefore, to avoid imprisonment, a probationer would do well to continue abiding by the terms and conditions of his/her probation even after the period of his/her probation, as long as no order of final discharge is issued by the court.