Upload file using Web Service (ASMX) WinForm c#

I use this tutorial upload file using web service to upload file using web service and it works fine.

My problem is that there is probably a file size limitation. When I tried uploading a 0.5MB file it worked fine. I tried to upload a larger file like 5MB and it did not upload.

Is there any limitation? If so, what is the limitation and how is it changed?