Hadith: The Messenger of Allah (may Allah’s peace and blessings be upon him) cursed the woman who fixes hair extensions (to another) and the woman who has them fixed for her, and the woman who does tattoos and the woman who has them done for her

عن عبد الله بن عمر رضي الله عنهما قال: «لعن النبي صلى الله عليه وسلم الوَاصِلَةَ والمُسْتَوْصِلَةَ، والوَاشِمَةَ والمُسْتَوشِمَةَ».
[صحيح] - [متفق عليه]

‘Abdullāh ibn ‘Amr (may Allah be pleased with him) reported: The Messenger of Allah (may Allah’s peace and blessings be upon him) cursed the woman who fixes hair extensions (to another) and the woman who has them fixed for her, and the woman who does tattoos and the woman who has them done for her.
Sahih/Authentic. - [Al-Bukhari and Muslim]

Explanation

This Hadīth proves that fixing hair extensions is prohibited for women, as well as making tattoos for the sake of beauty and adornment. These acts are major sins for the following reasons: 1. Adding hair extensions involves cheating and imitation of the Jews, who were the first to add hair extensions. 2. Making tattoos constitutes change of the creation of Allah, the Almighty. Hence, both the one who does such acts and the one who has them done for her are cursed.