David McNamara made the error before Manchester City's home game against Reading on 26 October after leaving his coin in the dressing room.

The Football Association said he "accepted a charge of 'not acting in the best interests of the game'".

A coin toss to decide kick-offs is a requirement under the laws of the game.

In this case, it involved England and Manchester City skipper Steph Houghton and Reading captain Kirsty Pearce, before the teams shared a 1-1 draw.

FA women's refereeing manager Joanna Stimpson told The Times that the McNamara's mistake was "a moment of madness".

She added: "The referee forgot his coin and in that moment, in a TV game, he was really pushed for time.

"He should have been more prepared, he should have had a coin. It was disappointing, it's not appropriate, it's very unprofessional."

McNamara's ban will last from Monday, 26 November to Sunday, 16 December.

An FA spokesperson said: "The FA can confirm that referee David McNamara has been suspended for 21 days, starting from Monday 26 November, after accepting a charge of 'not acting in the best interests of the game'.

"This follows an incident in the FA WSL match between Manchester City and Reading on Friday 26 October when he failed to determine which team would kick off the match by the toss of a coin, as required by the Laws of the Game."