Many nationally important infrastructure projects would simply not get off the drawing board were public authorities not equipped with the power to compulsorily purchase private land for the public benefit. When it comes to paying compensation, however, what happens if the owner of relevant land cannot be identified?

The Upper Tribunal (UT) addressed that question in the context of a local authority's compulsory acquisition of land to make way for an airport relief road. Although all notification and publicity requirements had been met, the owners of five parcels of land that had been made the subject of a compulsory purchase order (CPO) had not come forward and their identities remained a mystery.

Giving guidance on the issue at the council's request, the UT noted that, after a CPO is confirmed, Section 5 of the Compulsory Purchase Act 1965 requires acquiring authorities to serve a notice to treat – an invitation to participate in negotiating the amount of compensation – on all those with an interest in the land acquired.

That requirement is, however, subject to an important qualification: there is no duty on an acquiring authority to serve notices to treat on persons with an interest in the land whose identity cannot be discerned after making diligent inquiry.

The inclusion of that qualification is, the UT noted, hardly surprising: if persons with an interest in relevant land have not come forward during the CPO confirmation process, despite all required steps having been diligently taken to bring the matter to their attention, an invitation to participate in negotiation would be an empty gesture.

Appropriate compensation in respect of the five parcels had already been assessed. The UT declared that the council was entitled to pay the money into the Court Funds Office. Thereafter, it would lawfully acquire absolute title to the parcels, the smallest of which measured only one square metre, by executing unilateral deed polls.