(41)ESMA should regularly review the recognition of third-country CCPs as well as their classification as Tier 1 or Tier 2 CCPs. In that regard, ESMA should consider amongst others, the changes in the nature, size and complexity of the third-country CCP's business. Such reviews should take place at least every five years and whenever a recognised third-country CCP has extended or reduced the range of its activities and services in the Union. Where, following that review, ESMA determines that a Tier 1 CCP should be classified as a Tier 2 CCP, ESMA should set an appropriate adaptation period not exceeding 18 months within which the CCP should comply with the requirements applicable to Tier 2 CCPs.