One of the most practical instruments for securing the highest degree of harmonization is Recommendations that have been adopted by the WCO Council. While Recommendations are not binding instruments they can be formally adopted with the condition for application that implicitly commits administrations, insofar as possible, to implementing its provisions.

With regard to Customs procedures and practices the Recommendations on matters of Customs Technique are mainly intended

• to promote co-operation between Customs administrations;
• to standardize Members' practices regarding duty relieves, repayment or remission;
• to facilitate the international transport of goods and travel and tourism;
• to promote the harmonized use of information technology;
• to facilitate and expedite the implementation of certain international Conventions;
• to simplify and harmonize Customs documents;
• to ensure that adequate legal remedies are available to the taxpayer.

It was decided, at the Council's 21st Session, that "Recommendations lending themselves to such action should be brought to the knowledge of non-Member countries" through the United Nations Regional Economic Commissions.

At its 131st/132nd Sessions, the Permanent Technical Committee agreed that Customs Technique Recommendations should comply with the following principles :

• Customs Technique Recommendations should not be put on an equal footing with treaties within the meaning of the Vienna Convention on the law of treaties.

• Where a Recommendation contains more than one basic idea, each should be the subject of separate paragraph, a "RECOMMENDS" or an Annex.

• If necessary, Recommendations should specify towards whom an obligation is being assumed.

• With regard to successive Recommendations dealing with the same subject, it is necessary toreconsider, in each case, whether or not the new Recommendation should incorporate the substance of the earlier version.

• It is for the Council to decide, on the basis of proposals made by the competent Committee, whether an existing Recommendation should be retained when a new Recommendation on the same subject has been accepted.

• The conditions of application of a Recommendation are a matter for the State of Customs or Economic Unions accepting it, on the understanding that the party concerned is implicitly committed to implementing, insofar as possible, the provisions it has accepted. In any event, a State or Customs or Economic Union should not accept a Recommendation if unwilling to implement its main objectives.

At its 77th/78th Sessions, the Council adopted the Permanent Technical Committee's proposal for expanding the audience for Customs Technique Recommendations by making it possible for Council Members and non-Members of the Council as well as for Customs or Economic Unions to accept those Recommendations.

Situation Regarding Acceptances of WCO Recommendations (18 May 2016)

Recommendations Concerning Co-operation Between Administrations

1. Treatment at an International Level of Customs Technical Questions (30 November 1956) [ru]
2. The Communication of Information Concerning the Customs Status of Goods (22 May 1963) [ru]
3. Facilitate the Temporary Exportation of Goods Sent from one Country for Manufacture, Processing or Repair in Another (3 December 1963)
4. Note for the use of the Information Document
5. Technical Co-Operation in Customs Matters (18 June 1981)

Recommendations Concerning Duty Reliefs, Repayment and Remission

1. The Repayment or Remission of Duties on Goods Refused by the Importer as not Conforming to Contract (28 November 1957) [ru]
2. Tax-Free Shops (16 June 1960)
3. Repayment or Remission of Import Duties and Taxes on Goods Destroyed or Lost (5 Dec 1962) [ru]
4. Free Admission of Removable Articles Imported on Transfer of Residence (5 December 1962) [ru]
5. The Refund of Import Duties and Taxes on Shortages (5 December 1962)
6. Reimported Goods (6 June 1967) [ru]
7. The Free Admission of Gift Consignments (11 June 1968)
8. To Expedite the Forwarding of Relief Consignments in the Event of Disasters (8 June 1970) [ru]
9. The Customs Treatment of Products Imported for Testing (5 June 1972) [ru]

Recommendations Concerning Transport, Travel and Tourism

1. The Use of Temporary Importation Papers in Respect of Radio and Television Vans (1 Dec 1955)
2. The Temporary Admission of Radio and Television Vans (9 June 1977) [ru]
3. The Temporary Admission of Radio-Television Production and Broadcasting Equipment (13 June 1985) [ru]
4. The Customs Treatment of Provisions Carried in Restaurants Cars, Pullmans Cars, Sleeping Cars and Similar Cars of International Express Trains (16 June 1960) [ru]
5. The Customs Treatment of Registered Baggage Carried By Train (5 June 1962 amended on 21 June 1988)
   1. Annex: Customs Declaration for Registered Baggage
   2. Customs Declaration for Registered Baggage: Notice to Passengers
6. Customs Sealing Systems in Connection with the International Transport of Goods (11 June 1968) [ru]
   1. Appendix- Technical Specifications
7. The Application of a Flat Rate Assessment System to Goods Sent in Small Consignments to Private Individuals or Carried in Travellers' Baggage (Flat Rate Assessment) (11 June 1968) [ru]
8. Guidelines on Dual Channel Systems in Airports - Preamble [ru]
9. A Simplified Customs Control Based on the Dual - Channel System of Passengers Arriving by Air (8 June 1971) [ru]
10. A Simplified Customs Control Based on the Dual - Channel System of Passengers Arriving by Sea (5 June 1972) [ru]
11. Lighters Carried by Lash or Similar - Type Vessels (5 June 1972) [ru]
12. Measures to Facilitate the Application of the ITI Convention (18 May 1973)
13. The Temporary Admission of Special Equipment Carried in Vehicles used for or in Connection with the Transport of Radio - Active Materials (9 June 1977)
14. The Establishment of Links Between Customs Transit System (16 June 1982)
15. The Acceptance of ATA Carnets in Connection with Temporary Admission (25 June 1992)
16. The Acceptance of CPD Carnets in Connection with Temporary Admission (25 June 1992)
17. The recommendation of the Customs Co-operation Council concerning the use of advance passenger information (API) and Passenger Name Record (PNR) for efficient and effective customs control (June 2012)
18. Recommendation on CSDs (Container Security Devices) (June 2013)
19. Recommendation of the Customs Co-Operation Council Concerning the Use of Advance Passenger Information (API) and Passenger Name Record (PNR) for Efficient and Effective Customs Control (June 2015).
20. Recommendation of the Customs Co-Operation Council on the Guiding Principles for Data Quality (June 2015).

Other Recommendations

1. Samples Regarded as being of Negligible Value within the Meaning of the International Convention to Facilitate the Importation of Commercial Samples and Advertising Material (30 November 1956) [ru]
2. The Adoption of a Lay-Out Key for the Goods Declaration (Outwards) (1 June 1965)
   1. Annexes
3. The Right of Appeal in Customs Matters (6 June 1967) [ru]
4. The Adoption of a Standard form of Certificate of Origin (16 January 1973)
5. Customs Requirements Regarding Commercial Invoices (16 May 1979)
6. The Single Goods Declaration (26 June 1990)
7. The Use of the Glossary of International Customs Terms (6 July 1993)
8. The Protocol Against the Illicit Manufacturing of and Trafficking in Firearms, their parts and Components and Ammunition, Supplementing the United Nations Convention Against Transnational Organized Crime (29 June 2002)
9. Unique Consignment Reference (UCR) (26 June 2004) [ru]
10. The recommendation of the Customs Co-operation Council on the dematerialization of supporting documents (June 2012)
11. Guidelines on acceptable and unacceptable terms for the description of goods (March 2015)
12. Recommendation of the Customs Co-Operation Council concerning the use of trader identification number (TIN) (June 2018)