Estate agents lose an average of £4,123 in commission for every property sale that falls through, research from Propertymark shows.

The cliff edge created by the stamp duty holiday, whether it ends in March or June, will cause a major financial loss to the industry as many transactions will fall through if not completed by the deadline.

Almost a third of house sales fell through in January as buyers nervously eyed the looming end of the stamp duty holiday, according to Rightmove.

Propertymark, along with insight agency Opinium, surveyed its estate agent members from across the UK to reveal that failed sales are a problem for 42% of businesses, with a further 24% stating they are a substantial problem.

Four in five – 82% – agents say the loss of revenue has the biggest impact on their business, followed by the waste of human resources at 61%.

In the last year, an average of 17 sales have not completed per estate agent branch.

Failed property transactions also have a costly impact on the consumer, resulting in them losing £1,571 on average.

Mark Hayward, chief policy advisor, Propertymark said: “We have continually called on government to rethink the timings of the stamp duty deadline and the recent speculation of an extension will be good news for the sector. However, extending the holiday until June will create another cliff edge and purely push back the increase in the number of failed sales as we approach the new deadline.

“We need government to consider a tapered end to the holiday so that buyers aren’t forced to pull out at the last minute and the property market can continue to thrive.”