There is a maximum file size of 300 MB (that's 300000 KB). Simple text files such as Word, Excel, PDF, etc. will NOT hit this limit. Only data intensive files such as a very large quickbooks file may exceed this limit. Should you have a file larger than 300MB you can try uploading multiple segments, or you can use this alternate uploader. Please contact our office at (905) 277-9499 and confirm with Lisa Grossman if you need to use the alternate uploader.