Born in
Kazanlak, Yanchev's first club was local club
Rozova Dolina, before he moved to the squads of
Naftex Burgas. In the summer break of 2000
CSKA Sofia signed Yanchev. With CSKA he became a champion of Bulgaria for 2003 and 2005. After the end of 2004–05 season, Yanchev transferred to Greek side
Kallithea. Year later, as a free agent he signed with
Randers, spending one season in
Danish Superliga. In 2007, Todor returned to Bulgaria, to join CSKA Sofia for the second time. In 2008, he became a champion of Bulgaria for third time and won
Bulgarian Supercup. In the summer of 2009 he, as well as
Kiril Kotev and
Yordan Todorov, stayed in the club although the club was facing a big financial crisis, showing very stable level of play proving why he has been the team captain. In 2012 Yanchev was suspended for 3 months after he failed a
drug test for
methylhexanamine doping. The defensive midfielder, was one of eight players who was fired by CSKA Sofia on 27 July 2012 and he was appointed for assistant coach, but on 6 August 2012 he was brought back in the first team, because of problem with the registering of the new players. On 20 October 2012, he played for 22nd time in the
Eternal derby, wherein CSKA won 1–0. On 7 January 2013, after leading the team of CSKA to the first official winter training session, Toshko gave his resignation to the Bulgarian Football Union and is no longer a player for CSKA. He decided to leave
CSKA Sofia as a show of support for manager
Stoycho Mladenov who had been sacked. On 21 January, it was announced that Yanchev would join Slavia Sofia on a free transfer. In July of the same year he returned to CSKA Sofia for the third time, after the club changed its ownership. ==Managerial career==