There is no explicit text from Hz. Peygamber (sallallahu aleyhi ve sellem) specifying a minimum waiting period between two Umres. Scholars have differed on this matter. Some scholars hold that there is no waiting period — a person may finish one Umre, exit to Tan'eem, enter a new ihram, and perform another Umre immediately. Others recommend waiting until the hair grows back sufficiently to be cut again, as cutting the hair is one of the rites of Umre.
Sheikh Ibn Baz stated that there is no prescribed minimum time between two Umres. A person may perform Umre on behalf of different deceased relatives in succession during the same trip. He considered each Umre to be an independent act of worship with its own reward. However, he noted that spending time in other forms of worship — such as Tavaf, namaz, and Kur'an recitation — may be more beneficial than rushing between repeated Umres.
Sheikh Al-Albani held a different view, stating that repeating Umres in quick succession during the same trip has no basis in the Sunnah. He noted that Hz. Peygamber performed only four Umres in his entire life, each during a separate journey, and never performed multiple Umres in one trip. He sunnet following Hz. Peygamber's example by focusing on worship within the Haram rather than exiting repeatedly for additional Umres.