If someone tells others about doing sinful deeds that he never did, is that regarded as committing sin openly?

Firstly:

We praise Allah Who has enabled you to repent and we ask Him, may He be exalted, to make you steadfast therein. But in order to perfect your repentance, you must inform those whom you told about that that what you told them was not true; rather it was a lie, and you must warn them against those sins, lest they think that you are one of those who commit these sins, and so that you will be safe from the sin of encouraging shameful deeds among the believers.

You should understand that committing sin openly refers to when a person commits a sin in secret, then tells others that he committed that sin.

Al-Bukhari (6069) and Muslim (2990) narrated that Abu Hurayrah (may Allah be pleased with him) said: I heard the Messenger of Allah (blessings and peace of Allah be upon him) say: “All of my ummah may be forgiven except those who commit sin openly, and it is part of committing sin openly for a man to do something at night, then in the morning when Allah has concealed him he says: O So and so, I did such and such last night, when his Lord had concealed him all night, but in the morning he discloses that which Allah had concealed for him.”

For more information, please see the answer to question no. 3365 .

Secondly:

If someone tells someone else that he committed a particular sin, when he did not do it, and in fact he is lying about it, this is more abhorrent in terms of committing sin openly than one who commits the sin, then speaks openly about it. That is because he has combined lying – which is a major sin – with encouraging shameful deeds among the Muslims and making them seem insignificant to people, concerning which there is a warning, as Allah, may He be exalted, says (interpretation of the meaning): {Indeed, those who like that immorality should be spread [or publicized] among those who have believed will have a painful punishment in this world and the Hereafter} [an-Nur 24:19].

Moreover, it is not far-fetched to suggest that the one who claimed to have committed a sin, when in fact he did not do it, to suggest that he is a partner in sin with the one who committed that deed, especially if he has an inclination towards that sin, or he said that by way of expressing approval for it and wishing that he had the opportunity to do it, as we see in the well-known hadith of Abu Kabshah al-Anmari: “There are four types of people in this world: (the first of whom is) a person to whom Allah grants wealth and knowledge, so he fears his Lord with regard to it, upholds his ties of kinship with it, and acknowledges the rights of Allah concerning it – he is of the highest status. (The second is) a person to whom Allah grants knowledge but He does not grant him wealth, so he is sincere in his intention and says: If I had wealth, I would do the same as So and so does. He will be rewarded according to his intention and their reward will be the same. (The third type) is a person to whom Allah grants wealth, but He does not grant him knowledge, so he squanders his wealth without knowledge; he does not fear his Lord concerning it, he does not uphold his ties of kinship with it and he does not acknowledge the rights of Allah concerning it – he is of the worst status. (And the fourth type is) a person to whom Allah does not grant either wealth or knowledge, so he says: If I had wealth, I would do the same as So and so does. He will be requited according to his intention and their burden of sin will be the same.”

Narrated by at-Tirmidhi (2325), who said: It is hasan sahih. It was classed as sahih by al-Albani.

He only deserves to be regarded as a partner in sin with the one who does it because of his bad intention and his wishing that he could be a partner with him in his action. So how about the one who intends to do that, and wishes to do it, then he tells others that he did do it, but he is lying and claiming to have done something that he never did.

We ask Allah to bless us and you with pardon and well-being, and to enable us and you to repent sincerely.

And Allah knows best.