Agents who are using perfectly legitimate sources to source new leads should nevertheless be very careful that they are not breaching the Data Protection Act.

The warning from the Information Commissioner’s Office comes amid evidence of huge growth within the industry over the last three years – and increasing competition and touting for listings.

Agents – and others – have been warned that they should take into account how people might “reasonably” view receipt of unsolicited marketing material.

It is perfectly legal for any person, company or organisation to buy the “open register” – a version of local electoral rolls – for direct marketing purposes, although a high opt-out rate of some 40% makes the lists less valuable.

Other information about people is also readily and publicly available – for example, via the Land Registry.

Information can also be acquired in the form of marketing lists where people have agreed to receive information.

However, a spokesperson for the Information Commissioner’s Office told Eye: “Just because information is available from a readily accessible source, this does not mean it can be used for any purpose.

“Any organisation processing this information must comply with the Data Protection Act, and this means only using the data in ways which are fair.

“Organisations should consider the reasonable expectations of those people concerned before using the data or combining it with other sources of data in order to target unsolicited marketing material.”

The spokesperson added: “If an estate agent is processing personal data then they must, by law, register with the ICO.

“Not to do so is a criminal offence and can be punishable by a fine at magistrates’ or crown court.”

Eye asked for up-to-date information as to how many estate and letting agents have registered with the ICO.

Businesses – rather than branches – have to be registered, although brands within a group that operate as separate businesses would have to register in addition to their parent company.

We were given these figures, making them very up to date:

Limited company estate agents: 3,960

Limited company letting agents: 2,160

LLP estate agents: 173

LLP letting agents: 50

‘Other’ estate agents: 407

‘Other’ letting agents: 212

Partnership estate agents: 329

Partnership letting agents: 91

Plc estate agents: 13

Plc letting agents: 1

Sole trader estate agents: 716

Sole trader letting agents: 438

The figures show that a total of 8,550 agency businesses are currently registered.

The categories do not include any for online agents.

The 8,550 figure for the number of businesses compares with research by Rightmove and TPO, reported by Eye in August, that there are 20,000 estate agency and letting agency branches.

In 2010, there was a big crackdown on agents that had not registered with the Information Commissioner’s Office.

In June 2011, the ICO announced that 4,336 estate agents and 1,764 letting agents had registered.

That gave a total of 6,100 agents. Even if there were still a number of agency businesses not signed up, it does suggest that the industry has grown enormously since 2011, by anywhere up to some 2,450 businesses since then.