Landlords around the UK may soon be forced to make sure they are fully transparent with all charges during the marketing of their properties, after the country's advertising regulator outlined its intention to crack down on the practice of scrimping on important details.

This comes after it was announced that the Advertising Standards Authority (ASA) had ruled against a lettings agent who had advertised a property for rent but failed to include the details of the admin fee alongside details of rental pricing.

The strength of the private rented sector in the UK at the moment, buoyed by increased demand, has meant that those in the market for buy-to-let properties have been increasing portfolios. This will prove to be another important undertaking in terms of their responsibilities, alongside things like landlord insurance and making sure they declare income for taxation purposes.

It was advised by the ASA that anyone who is advertising a property to potential tenants must say upfront whether there is a charge included that is not part of the rental fee.

In its example, it said that if there is an additional charge, prices should be outlined as "£1,500pcm + £150 admin fee" or similar to give full transparency over costs and avoid accusations of trying to exploit consumers in a busy marketplace.

For those homes where working out other fees beforehand is not a possibility, the regulating body said landlords should simply indicate clearly that one will exist once the tenancy has been agreed.

Guy Parker, chief executive of the ASA, said: "Hidden fees are not only unfair, they hit those who are struggling hardest. Our ruling today makes clear that letting agents need to get their houses in order and treat potential tenants fairly.

"Renting a property is a significant commitment. And for those who are new to the rental market, like students, navigating it can be particularly difficult. That’s why the ASA is clamping down on letting agents who hide fees."