There are five criteria for carbon offsets that are recognized by all climate bodies and are outlined by the World Resources Institute (WRI).
#1 Real
Offsets must represent one ton of carbon dioxide equivalent emissions that are reduced or sequestered as a result of an activity taken for that purpose.
#2 Permanent
Carbon offsets are considered permanent if they are not reversible.
#3 Additional
Additionality means that the carbon offsets were generated by activities that would not have occurred without a carbon marketplace as an incentive.
#4 Verifiable
Emission reductions and sequestration must be monitored and verified.
#5 Enforceable
Enforceable carbon offsets must be tracked and logged so that ownership is verifiable and an offset may only be sold once.
