What should I do with my ED visa before leaving Thailand?

If you don't cancel your Educational (ED) visa before leaving Thailand, it won't directly impact your departure, but it may lead to complications for future visa applications. An ED visa itself cannot be canceled, but if you have an 'Extension of Stay', you need to cancel it at the immigration office before you leave. If you leave without canceling the extension, it might not stop you from applying for a new visa later, but you could face issues when applying for further extensions at the immigration office. It's crucial to understand the difference between a visa and an extension; the visa allows you to stay until the stamped date regardless of changes in your situation, whereas extensions often require cancellation.