Once a person has been “attuned,” i.e., made able to channel Reiki at will, they can perform Reiki and start doing sessions for others for a fee. (Most states have little if any, regulations around Reiki. But be sure to check your state!) The question lies more with the practitioner’s confidence than their training level. Confidence comes with practice.
Reiki training is offered in 3 levels or degrees. Precisely what is taught at each level has some variation, depending on the priorities and experience of the individual instructor.
For example, the energetic bandwidth of Reiki has several individual frequencies that can be emphasized in order to promote a specific intention. We can these “symbols.” Some instructors include the first symbol in the first class; others wait until the 2nd class to give any symbols.
Typically the first level or degree focuses on the physical expressions and level of life. The student learns to do self-Reiki and learns the basics of doing Reiki for others.
In the 2nd level or degree, the student learns to channel energies specific to emotional healing, and to be able to do remote, or distance healing, including healing past traumas and issues.
The 3rd level or degree originally was only to initiate someone to be a teacher, able to “pass attunements”, as if the 3 symbols learned thus far are ‘all there is”. Some masters realized the 3rd-degree symbol was also effective for healing work, and also that many people who want to practice Reiki do not want the responsibility of teaching. Therefore, some masters divide the master level into 2 levels and call them Reiki Master and Reiki Master Teacher. Many Masters offer 2 more symbols in their Master class, depending on their lineage.