on 4 september 2009, tonev scored his first goal for the bulgaria u21 in the 3–0 home win against kazakhstan u21 in a uefa european under-21 football championship qualifier. on 9 september 2009, he was sent off for a dangerous tackle on guillermo molins in the 90th minute of the 1–2 away loss to sweden u21. on 9 february 2011, tonev scored a goal in a friendly match against cameroon.