To dream that you are doing forgery (of a signature, a painting, etc), suggests that you are acting badly in some way in your real life. You have a flaw in your character which makes you willing to deceive and take advantage of others for your own gain.
If you dream of somebody else doing forgery, you may feel cheated from what you rightly deserve.
It is a bad omen to dream that you are guilty of Forgery. But it is a good sign if someone else forges your signature.
To dream that your name has been forged on a check or other document is a warning against being too trustful of your business associates.