The Land Registry has admitted that leaseholders seeking to update or extend their leases are facing delays of up to six months.
It has also hired an extra 1,000 staff and put others on overtime to reduce the backlog, it says.
Although Land Registry will expedite leasehold update and extension applications within two weeks if a vendor can prove an offer has been made and the sale is proceeding, this means thousands of potential vendors are being held back by the delays.
The organisation has also revealed that it received 8,000 fast-track requests over the past four months.
It told BBC Radio 4’s You and Yours programme that although overall it processed 96% of all its property transaction related applications, it had fallen significantly behind in its leasehold work.
Simon Law of the Society of Licensed Conveyancers (left), who was interviewed during the programme, blamed the delay on staff reductions following the financial crisis and ensuing housing market crash, which led to experienced staff leaving the Land Registry.
He told presenter Winifred Robinson that these problems have been an issue for his members for seven years.
“They haven’t been able to increase their staffing levels enough to meet the increasing demand,” he said.
“If you need to get a lease updated to replace an obsolete maintenance clause, for example, or you need the term to be increased before you look to sell, a six-month delay is a long time to be sat waiting.
“And if you do find a buyer, you have no idea if they will be happy to wait for that time.”
Law says the answer is to speed up the introduction of electronic deed management at the Land Registry, although he pointed out that it will take a while to reduce the backlog; it takes at least six months to train Land Registry staff to handle leaseholds.