How do you confess a lie? Do you confess that you lied or do you have to tell the lie? Do you need to confess who you lied to like your husband, friend or coworker? Or can you just confess that you told a grave lie?
You need to confess how many times you lied and any circumstances that might change the nature of the sin.
For example: lying about something very serious versus lying about something insignificant; lying to a stranger who did not have a real right to know something versus lying to your spouse about something which he had a right to know, etc.
Only mortal sins need to be confessed in number. If it is a mortal sin (grave matter, full knowledge, and deliberate consent) then tell the priest how many times you lied. If it is habit, and you don’t know how many times you have lied, at least tell the priest that you have lied many times. If he needs more information, he will ask.
Again, it all depends on the serious nature of the lie, and whether you knew what you were doing at the time and if you were acting in free will or not.
Even if it is not a mortal sin, it will do you good to confess the lie to the priest.
you confess only what needs to be said to communicate the nature of the sin and how often or frequently you committed it. examples
I lied 3 times, once about a grave matter.
I have a habit of habitual lying, several times a week, usually about small matters, but it is a damaging habit I am trying to break, please help me.
I told a serious lie to my husband which has caused harm to our relationship (you tell more circumstances only to show the gravity of the sin, but still keep it brief.)
priest does not need the backstory, he will ask for details if he needs them to counsel you.