The following documents govern the ESO procurement activities:

• General Conditions of Purchase Orders, Munich, May 2007
• General Conditions of Purchase Orders, June 2013
  
• General Conditions of ESO Contracts: Version applicable as from June 2013
  
  • Previous versions: Munich, October 2011
  • Munich, December 2009
  • Munich, May 2007
• Conditions Governing Calls for Proposals and Contracts for the VLT Instrumentation, Munich, December 2009
  
  • Annex 1: General Conditions Governing Invitations to Tender and Tenders, Munich, May 2007
  • Annex 2: General Conditions of ESO Contracts, Munich, December 2009
  • Annex 3: Copy of the Protocol on the Privileges and Immunities of ESO
  • Annex 4: Policy for Guaranteed Time Observations (GTO)