Styles began her Countdown career on 7 November 2012. In her début appearance against Philip Jackson, her spot of the impressive nine-letter word PLANETOID helped her to a final score of 114, the highest of the series. She proceeded to win seven more heats, getting no further centuries but also no scores below 82, to complete an octochamp run and become #3 seed for the series finals. After seeing off the quarter-final challenge of Tia Corkish rather easily, she came up against #2 seed David Barnard in the semis. Styles beat him with ISOLATED and MATERIEL, but he fought back with SEDATING to make the scores dead level going into the crucial conundrum BLUEINDIA. Styles solved this to advance to the grand final. Here, however, she emerged runner-up after falling to #1 scorer Paul James.
Styles returned to Countdown in January 2016 as a participant in Championship of Champions XIV. In her opening game here, she notably spotted UNREALIST, a nine-letter word only added in the most recent OED update. However, her opponent, the Series 68 champion Giles Hutchings, found a nine here too and was indomitable in all other rounds, dropping only three points from perfection, and Hutchings emerged the winner 132 – 73.
In 2014, she appeared as a contestant in the revival of Fifteen to One.
|#||Date||Type||Contestant 1||Score||Contestant 2||Guest||Lex||Max|
|5584||7/11/2012||P||Philip Jackson||65 – 114||Heather Styles||Janet Street-Porter||Susie Dent||138|
|5585||8/11/2012||P||Heather Styles||89 – 67||Rhondda McCracken||Janet Street-Porter||Susie Dent||132|
|5586||9/11/2012||P||Heather Styles||98 – 56||Keith Walton||Janet Street-Porter||Susie Dent||139|
|5587||12/11/2012||P||Heather Styles||87 – 65||Tracy Turner||Connie Fisher||Susie Dent||129|
|5588||13/11/2012||P||Heather Styles||82 – 73||Alma Cox||Connie Fisher||Susie Dent||118|
|5589||14/11/2012||P||Heather Styles||89 – 49||Max Plaice||Connie Fisher||Susie Dent||119|
|5590||15/11/2012||P||Heather Styles||88 – 20||Stuart Gillespie||Connie Fisher||Susie Dent||120|
|5591||19/11/2012||P||Heather Styles||90 – 57||Mike Whinnerah||Gyles Brandreth||Susie Dent||132|
|5610||17/12/2012||QF||Tia Corkish||65 – 100||Heather Styles||Alistair McGowan||Susie Dent||119|
|5613||20/12/2012||SF||Heather Styles||91 – 81||David Barnard||Alistair McGowan||Susie Dent||117|
|5614||21/12/2012||GF||Heather Styles||51 – 106||Paul James||Alistair McGowan||Susie Dent||118|
|6279||5/01/2016||CP||Heather Styles||73 – 132||Giles Hutchings||Gloria Hunniford||Susie Dent||135|