You can claim your free credit easily through the ISIC website.

To do this:

1. Visit the ISIC website

2. Find and select the Hostelworld $5 Benefit

3. Click the link to get to the Hostelworld website

4. On the Hostelworld website, sign up for a Hostelworld account using your ISIC card details and your credit will be applied to your account When you receive your credit, you’ll be able to start using it straight away.