Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- Removable tattoos involve drawing on the surface of the skin without puncturing it with needles or any other object.
2- Removable tattoos, used for adornment and accepted in some cultures, are permissible because they do not involve skin penetration and are easily removed.
3- It is permissible to sell and buy removable tattoos.
Answering your question, Dar Al-Ifta Al-Misriyyah, states:
Permanent tattoos
Tattoo as a term has two meanings. The first refers to permanent tattoos which involve injecting dyes into the dermal layer of the skin (containing blood capillaries) with a needle.
The prohibition of this kind of tattoo in Islam is based on authentic traditions that declare any individual who performs them on others or gets them done to be cursed.
Both al-Bukhari and Muslim reported through Abdullah ibn Umar that the Prophet (peace be upon him) cursed both the one who does tattoos and the one who has a tattoo done.”
Imam Ibn Hajar wrote in his book Fath al-Bari that tattooing is prohibited because it results in being cursed by God. Moreover, the tattooed spot is considered impure because blood clots form under the puncture wounds which need to be removed even if this causes injury unless there is a fear of ruining or hurting an organ. Only then is it permissible to keep the tattoo and repentance is sufficient to lift the sin. This applies equally to both men and women.
Removal of tattoos
As mentioned above, when the removal of tattoos necessitate causing injury or harm to the body it is impermissible to remove them. God says in the Quran, {And God wants to lighten for you [your difficulties]; and mankind was created weak.} (An-Nisaa 4:28)
We also read in the Quran:
{God intends for you ease and does not intend for you hardship… } (Al-Baqarah 2:185)
{He has chosen you and has not placed upon you in the religion any difficulty…} (Al-Hajj 22:78)
{God does not charge a soul except [with that within] its capacity. It will have [the consequence of] what [good] it has gained.} (Al-Baqarah 2:286)
Praying while having tattoos
As for praying while having tattoos, it is permissible because the matter is classified under excusable impurity. Imam al-Nafrawi al-Maliki said, “If someone has a forbidden tattoo, he is not obliged to remove it with fire; it is an excusable impurity and prayers are valid while having it.”
Fasting is permissible as well because it has nothing to do with having a tattoo.
Removable tattoos
The second meaning of the term refers to removable tattoos that fade in time or by water or any other substance. Removable tattoos involve drawing on the surface of the skin without puncturing it with needles or any other object. Removable tattoos, used for adornment and accepted in some cultures, are permissible because they do not involve skin penetration and are easily removed. Based on the above, it is permissible to sell and buy removable tattoos.
Almighty Allah knows best.
Source: Dar al-Ifta al-Misriyyah