Tattoo as a term has two meanings. The first of which is the permanent tattoo which includes the process of stitching a needle into the skin until blood oozes out and then different kinds of dyes are placed in these opening wounds to penetrate through the body and remain there with no removal. This kind of tattoos are prohibited in Islam according to the authentic traditions in which both the one who does tattoos and the one who draws them are cursed. Both al Bukhari and Muslim reported through ‘Abdullah ibn ‘Umar that the Prophet (peace be upon him) cursed the one who does tattoos, and the one who has a tattoo done.”

The scholar al Hafiz ibn Hajar said in his book (Fath al Bari) that having a tattoo is prohibited because it causes cursing and the tattooed spot of the body is deemed impure because the blood is clotted in it and therefore needs to be removed even if this causes an injury unless there is a fear of ruining or hurting an organ, only then it is permissible to keep the tattoo and repentance would suffice in lifting the sin and both men and women are equal in this issue.

Therefore if the removal of tattoos will necessitate injuring the body or causing harm to it then it is disapproved to remove it. God says in the Quran, “And God wants to lighten for you [your difficulties]; and mankind was created weak”. (4:28) and He said, “Allah intends for you ease and does not intend for you hardship… “(2:185) and also, “He has chosen you and has not placed upon you in the religion any difficulty…”(22:78) and “God does not charge a soul except [with that within] its capacity. It will have [the consequence of] what [good] it has gained,” (2:286)

As for praying while having these tattoos on, it is deemed permissible because it goes under forgiven impurity. Imam al Nafrawi al Maliki stated “If someone has a forbidden tattoo, he is not obliged to remove it with fire and it is rather a forgiven impurity and prayers are valid with having it” and fasting is deemed valid as well because it has nothing to do with having the tattoo on.
The second meaning is the removable tattoo in which the drawing does not penetrate through the skin by the use of a needle or any other objects but rather the drawing is limited to the surface of the skin and it fades by time or by the use of water or any other cleaning substance. This kind of tattoo is permissible as it does not penetrate through the skin and is removed easily within a certain time limit. These removable tattoos are used for adornment and are accepted in some cultures.
Therefore, it is permissible to trade in selling and buying removable tattoos.