Hundreds of large companies purchase Renewable Energy Certificates (RECS or Guarantees of Origin (GOs) as they are called in the EU) in order to reduce their reported scope 2 emissions (emissions from the purchase of electricity). However, there is increasing recognition that there are problems with this approach. Firstly, existing evidence shows that buying certificates is unlikely to increase the amount of renewable generation or reduce emissions. Secondly, reporting zero emissions based on the purchase of certificates undermines the accuracy and relevance of GHG disclosures. The GHG Protocol, the international standard for corporate GHG reporting, is looking to revise its guidance on scope 2, and this talk discusses some of the options for how the guidance might be improved.