Errors when providing supporting documentation

The most common errors that occur when providing additional documentation are the following:

• Error 400: It usually appears on computers with a low data transmission speed or files that are too large. In these cases, it is recommended to send several files or fragment the file.
• File is not supported (format error, location, etc.). It is recommended that the file to be attached does not have a very long name, nor non-permitted characters (commas, periods, apostrophes, cedillas, &, quotation marks, etc.) or a size greater than that allowed in the corresponding document submission. It is also recommended that the file be located in the path C:/ AEAT If this path does not exist on your computer, you can create it to locate the file, since sometimes it is essential.
• The window to select the file does not appear: This is usually due to the browser settings or accessing the procedure from an incorrect link. We recommend that if you are using Windows, you contribute using Mozilla Firefox, Edge or Google Chrome, as Internet Explorer 8 or below does not support it.