A last-minute "bottleneck" of buy-to-let investors rushed to complete property sales before a stamp duty hike, estate agents said.
People buying second homes, including buy-to-let investors, will pay three percentage points above previous rates from Friday.
Martyn Baum, president of the National Association of Estate Agents (NAEA) said a rush of investors had been seen across the country.
Mr Baum said: "We have certainly seen huge pressure and demand to try to get deals done in the last week and it has come to a bottleneck. Estate agents and conveyancers have been trying to get deals through and extending their working hours. It has been a busy few days."
Mr Baum, who is based in Leicestershire, expects to see a period of readjustment in the housing market as the stamp duty hike takes hold, with bigger, more commercially-minded landlords still wanting to invest.
He said: "It's becoming more difficult and less appealing to be a landlord, but I do think that will give space and elbow room for first-time buyers. Mortgage rates are currently very attractive."
The NAEA recently reported demand for homes surged to a 12-year high in February, with more than eight in 10 (85%) estate agents reporting an increase in the number of investors flooding into the market.
As investors piled in, the proportion of homes being sold to first-time buyers fell. One in four (24%) sales made in February were made to first-time buyers - a decrease of five percentage points from January.
The new rates of stamp duty land tax (SDLT) will apply to purchases of additional residential properties in England, Wales and Northern Ireland.
In the recent Budget, the Government confirmed that big investors will not escape the stamp duty hike.
A consultation had considered whether it may be appropriate to have an exemption for investors buying at least 15 residential properties, but it was decided that there will be no exemption for significant property investors.
However, people who temporarily end up with two properties due to difficult circumstances, such as retirees downsizing into a smaller property but struggling to sell their original home, will be given some extra breathing space from the new stamp duty rate.
The Government decided purchasers will have 36 months rather than the originally proposed 18 months to claim a stamp duty refund, in the event that there is a period of overlap or a gap in ownership of a main residence.
In Scotland, SDLT has been replaced by the land and buildings transaction tax.
A hike in this tax is also coming into force in Scotland on the purchase of additional homes such as second homes or buy-to-let properties from Friday, with the aim of avoiding any potential distortions to the housing market in Scotland that could have come from the stamp duty hike for investors in the rest of the UK.
Landlords are also facing a financial squeeze due to restrictions on their tax breaks, while a ''wear and tear allowance'', which allows them to reduce the tax they pay, regardless of whether they replace furnishings in their property, will also be replaced by a new system that only allows them to get tax relief when they replace furnishings.
Earlier this week, the Bank of England unveiled proposals to crack down on buy-to-let lending. The Bank wants lenders to consider landlords' wider finances and not just their rental income. The proposals are being consulted on and if adopted, they could cut new approvals for buy-to-let mortgages by about 10% to 20% by the third quarter of 2018.
The Government has also indicated it will hand the Bank greater powers to intervene in the buy-to-let mortgage market by the end of the year amid concerns of a "bubble" emerging in this market.
The Association of Residential Letting Agents (Arla) found that nearly two-thirds (63%) of letting agents predicted the supply of buy-to-let properties would fall after the stamp duty deadline as landlords are pushed out of the market.
Nearly six in 10 (57%) Arla members believed rents would be pushed up once the stamp duty reforms came into effect, as increased costs for landlords were passed through to tenants. This is particularly high in London, where three-quarters (73%) of letting agents expect to see this happening.