A cooperation contract has been signed between Oslo municipality and the Norwegian Tax Administration as a part of Oslo municipality's fight against working life criminality, including illicit work and social dumping. Oslo municipality therefore requires a signed permission slip that gives Oslo municipality an extended right for an unlimited number of times to obtain information on its suppliers and sub-suppliers' tax and duty standing, as stated in the permission slip. The permission shall be signed by the winning tenderer after the award of contract letter has been received, but before the contract is signed.