Transactions were down by 2% last month, compared with the same period in 2017, according to non-adjusted HMRC data.
Between March and April sales plunged by 12%.
Overall there were 100,190 residential and 11,300 non-residential transactions last month, the figures showed.
Paul Smith, chief executive Haart estate agents said the figures were “disappointing” but the outlook is brighter.
He added: “Our own data shows that buyers are returning to the market in significant numbers, with branch registrations up 9% on the month in April and almost 40% on the year.
“House prices increased by a healthy 1.2% on last year. As the weather heats up, this increase in interest will convert into greater activity and more transactions.”
Jeremy Leaf, north London estate agent, said: “Looking forward, we expect more of the same as we enter the spring market, which sets the tone for a steady rather than spectacular rest of the year for activity.”
More supply needed
The government must provide more supply to give the market a needed kick into action, according to experts.
Kevin Roberts, director of Legal & General Mortgage Club said: “A lack of appropriate housing stock and rising demand continues to squeeze the bottleneck in our housing market.
“Preventing any real momentum from forming, it is limiting the options for those looking to step on the property ladder, or up, or downsize.
“For us to see a real push in numbers, we need the government to build around 300,000 homes per year to keep up demand.”