I will try to answer

EA Form is given by Company; hence anyone can actually fake an EA Form

Form BE is your tax Submission to IRB. If you do E-Filing:

Once you register for E-Filing, you will be given a password / username.

Once u login, the on-line BE Form is ready for you to fill in and make amendments, etc.

(a) once the Form has been submitted, you will be given a confirmed BE Form that certain Banks, Immigration will require as solid proof of Income

(b) I believe that there will also be a 'confirmation' from IRB on your actual Income, Tax to be paid and Final Tax payable / refundable. This Info is the same as your confirmed BE Form but in a summarised One Pager. Some ppl call this 'E-Filling Confirmation'. Banks, Immigration also accepts this 'E-Filing Confirmation' as proof of Income.

Hope its still correct and helpful.

If you apple for Credit Cards and Personal Loans, Banks will take your EA Form as good enough. However, some Banks ask for your EPF Statement to verify your monthly income

For Housing Loans, most Banks do ask for the BE Form.

The Form J is when u do Manual Filing, believe for E-Filing, its the 'E-Filing Confirmation' that I was talking about.

The EA form is issued by the Employer and it represents the salaries, commission, etc that the Company paid to you.

Hence, your question:

"if employee falsely declare higher income on his EA Form without employer's notice, will Gov / banks take legal action against that Employer?"

The Answer would be NO as it means that you have faked a EA Form and it is not the real EA Form issued by the Company..