City of Tshwane Metropolitan Municipality v RPM Bricks (Pty) Ltd

The City of Tshwane Metropolitan Municipality approved RPM Bricks (Pty) Ltd as an approved coal supplier under a tender agreement that required coal delivery by rail and any variation to be resolved by the municipal council in terms of s 38 of the Gauteng Rationalisation of Local Government Affairs Act 10 of 1998. Due to the unavailability of rail transport, municipal employees agreed with RPM Bricks that coal would be delivered by road at increased prices. RPM Bricks supplied coal at the higher prices, invoiced the municipality, and was paid for several months. The municipality later refused to pay outstanding invoices for December 2002 and January 2003, asserting that the price increases were invalid because the council had never resolved to vary the tender as required by statute. RPM Bricks sued for payment based on contract, alternatively enrichment, but abandoned the enrichment claim at trial.

The appeal was upheld with costs. The judgment of the High Court was set aside and replaced with an order of absolution from the instance with costs.

This case is a leading authority on the limits of estoppel against organs of state in South African law. It affirms the distinction between ultra vires acts and mere procedural irregularities, reinforces the doctrine of legality, and confirms that estoppel cannot be used to validate unlawful conduct by public authorities. The judgment is frequently cited in procurement, administrative, and local government law, especially in the context of tender variations and s 217 of the Constitution.