High-end agents are still recovering from the night that none will ever forget: the great Stamp Duty stampede.

Hours of drama, excitement, hits and near-misses followed the Chancellor’s surprise reform of Stamp Duty Land Tax.

Agents right across London, and in other affluent spots, worked with solicitors to pull off exchanges by the stroke of midnight.

Not all were successful, with some deals failing to hit the deadline and others falling through altogether.

Exchanges by midnight meant that buyers of properties worth roughly £1m or more could choose to pay Stamp Duty when it falls due at completion at the old – and for such buyers, significantly cheaper – rates.

There was a window of little over ten hours from the time George Osborne made his announcement to the striking of the clock.

Some solicitors were reportedly on £10,000 for a night’s work to get exchanges through – regardless of when subsequent completions take place.

The biggest single deal is thought to have been a £30m house in Surrey that exchanged at 11.45pm – saving more than £1.2m in SDLT with just quarter of an hour to spare.

The tightest deal was reported by Savills. It came in at 11.59pm and involved a client out in Australia on a Hells’ Angels’ tour at 5am his time. The deal was duly done.

Other deals also exchanged with seconds to spare. London agent Lurot Brand reported working with six sets of solicitors to get three deals through, getting the last email confirming exchange at 11.58pm. On one deal, the saving was £150,000.

One of the busiest agents was London agent Kinleigh Folkard & Hayward which progressed 23 properties through to exchange.

The homes ranged in price from £450,000 up to £3.3m, with one purchaser saving £78,750 in tax.

Solicitor James Gordon, partner at Sherrards Solicitors, a member of KFH’s conveyancing panel, said: “Within minutes of receiving news of the announcement we were reviewing our files to identify which of our clients would be better or worse off as a result of the stamp duty rate changes.

“We contacted any clients who would be adversely affected to advise them of the additional tax that would become due and some were prepared to take a view on any outstanding issues and exchange contracts regardless.

“One of my clients, a couple buying a house in SW4 for £3.25m, were facing an additional £76,250 in stamp duty.

“The sale had only just been agreed and I hadn’t even received any draft contract papers.

“However, the seller’s solicitor was extremely co-operative and stayed late to get the exchange done.”

Another busy agent was Douglas & Gordon which pushed through 11 deals.

Director Ed Mead said the last went through at 11.16pm and the maximum saving was £43,500. Three deals fell through on the night, however.

Chestertons also burnt the midnight oil. Its Kensington office reported that the buyer and seller of a £9m home in Kensington both dashed into the City and sat with their solicitors until the exchange was completed.

The Stamp Duty cost on that deal of £630,000 would have increased to £993,750 under the new regime, so a saving of £363,750 was made by concluding the deal before midnight.

The Chestertons Barnes office in south-west London reported that a buyer of a £3.75m house had his solicitor working late into the night, but managed to get it concluded before the clock struck midnight, saving £82,500 for the relieved purchaser.

Another buyer wasn’t so lucky and had to swallow the increase.

The firm’s Canary Wharf office also reported two transactions that were rushed through yesterday, saving £40,000 for each buyer.

Peter Ambrose of The Partnership, whose conveyancing clients come entirely from estate agents, said: “We had an absolutely mad day. I have never known anything like it.

“We had one £3.9m deal exchange despite the buyer having no deposit and no mortgage in place – that was how keen they were to push forward, standing to save £100,000.

“In another case, we had to get the client off the plane at Heathrow to get his signature. I don’t know how he managed it, because he was sitting on the plane ready to take off – but he did sign, with a £30,000 saving.

“We also had about six conditional contracts exchange – although what will happen to them, we don’t know. Sometimes it is better not to exchange at all than do so conditionally.”

Small independent Haus Properties was another caught up in the stamp duty stampede.

Jamie Lester said: “We had a number of last-minute attempts to exchange, including one at £980,000, saving the purchaser £2,550 and one at £2m which saved the purchaser £55,000.

“The lawyer of the latter had to cancel his wedding anniversary plans in order to get the deal done!”