QUESTION: Is it permitted to buy and wear new clothes during the Three Weeks until Rosh Chodesh Av?
by Rabbi Doniel Neustadt (culled from Torah.org)
ANSWER: As we mentioned earlier concerning appliances, only the type of clothes that require a shehecheyanu should not be bought during this time. Thus shoes, shirts, pants and all undergarments may be purchased and worn without restriction until Rosh Chodesh Av. One who never recites shehecheyanu on clothes, even on expensive ones,(5) could also purchase and wear expensive clothes during this time. Those who do recite shehecheyanu when putting on new clothes, may still buy and alter them until Rosh Chodesh Av but they may not be worn until after the Nine Days are over.(6) Mishnah Berurah(7) rules that on Shabbosos in the Three Weeks it is permitted to wear an item that requires shehecheyanu(.8) Other poskim are more stringent and do not permit wearing such clothes even on Shabbos.(9)
5 See Teshuvos Mahrshag 1:95
6 Mishnah Berurah 551:45; Kaf ha-Chayim 551:88: Harav S.Z. Auerbach (Shalmei Moed, pg. 478)
7 Mishnah Berurah 551:45 and Sha'ar ha-Tziyun 48. See also Kinyan Torah 1:109.
8 But only on Shabbos itself - it may not be worn for the Minchah on erev Shabbos; Bein Pesach l'Shavuos, pg. 293.
9 Chayei Adam 133:14; Kitzur Shulchan Aruch 122:2; Aruch ha-Shulchan 551:18.