43. One may buy an aliya or mitzva [e.g., pesichas ha’aron or hagba] in shul with maaser money if he had in mind to do so when he bought it. If he initially bought it without having in mind to pay with maaser money, it becomes a chiyuv and he may not subsequently decide to pay with maaser (ט"ז שם ).
44. However, some only allow using maaser for the difference between his bid and the previous bid. I.e., if someone bid fifty dollars and he bid sixty and got it, he would only be able to use ten dollars of maaser. This is because the shul would have gotten fifty non-maaser dollars regardless, so if he pays the entire amount with maaser, “maaser” as a whole loses out (של"ה מס' מגילה ענין צדקה ומעשר, הובא ברע"א גליון שו"ע סי' רמ"ט על הט"ז סק"א ). If he is in a shul of bnei Torah or poor people who all buy aliyos with maaser money, then he may pay the full amount with maaser.
45. Mi shebeirach money. One may pay money he pledged in a mi shebeirach from maaser (חזו"א ארחות רבינו ח"א סי' ש"ג ).
