IELTS is scored on a nine band scale. Each Band corresponds to different English competence. The Band Scores are in either whole or half Bands. The nine bands are described as such:

9 Expert User
Has fully operational command of the language: appropriate, accurate and fluent with complete understanding.

8 Very Good User
Has fully operational command of the language with only occasional unsystematic inaccuracies. Handles complex detailed argumentation well.

7 Good User
Has operational command of the language, though with occasional inaccuracies, inappropriateness and misunderstandings in some situations. Generally handles complex language well and understands detailed reasoning.

6 Competent User
Has generally effective command of the language despite some inaccuracies and misunderstandings. Can use and understand fairly complex language, particularly in familiar situations.

5 Modest User
Has partial command of the language, coping with overall meaning in most situations, though is likely to make many mistakes. Should be able to handle basic communication in own field...

4 Limited User
Basic competence is limited to familiar situations. Has frequent problems in use of complex language.

3 Extremely Limited User
Conveys and understands only general meaning in very familiar situations. Frequent breakdowns in communication occur.

2 Intermittent User
No real communication is possible except for the most basic information using isolated words or short formulae in familiar situations and to meet immediate needs. Has great difficulty understanding spoken and written English.

1 Non User
Essentially has no ability to use the language beyond possibly a few isolated words.

0 No Original English Used
No assessable information provided. Candidate may have failed to sit for the test