Eskom issued a Request for Proposals in August 2018 for boiler maintenance and outage repair services at fifteen coal-fired power stations. The RFP required, as a mandatory returnable, submission of a valid ISO 3834 welding certificate, failing which bids would be disqualified. Babcock Ntuthuko Engineering submitted a bid but did not include the ISO 3834 certificate by the closing date, instead stating that it was certified. After a clarification meeting (which Babcock attended) confirmed that submission of the certificate was mandatory, Eskom disqualified Babcock. Eskom ultimately awarded the tender jointly to Actom and Steinmüller, splitting the work between them. Babcock successfully reviewed the award in the High Court, which found the ISO requirement ambiguous and held the disqualification unlawful. Eskom, Actom and Steinmüller appealed to the Supreme Court of Appeal.