As per your query the IELTS result would be valid for three years from the date of your examination. Please check the following link:
Documents to show English language ability
The results of a specified English language test (IELTS, Occupational English Test (OET), Pearson Test of English Academic, or TOEFL iBT) that you took less than three years before lodging your application. You can also provide the results of a Cambridge English: Advanced (CAE) test, but the test must have been undertaken on or after 1 January 2015 and before lodging your application.