Siman 269
Presented here for study, not as a practical ruling. The Shulchan Aruch rules by Sephardi custom, the Rema's glosses by Ashkenazi custom, and the Kitzur follows Ashkenazi custom. For a practical question, ask your rabbi.
א נוֹהֲגִין לְקַדֵּשׁ בְּבֵית הַכְּנֶסֶת, וְאֵין לַמְקַדֵּשׁ לִטְעֹם מִיֵּין הַקִּדּוּשׁ אֶלָּא מַטְעִימוֹ לְקָטָן, דְּאֵין קִדּוּשׁ אֶלָּא בִּמְקוֹם סְעֻדָּה וְעַיֵּן לְעֵיל סי' רע"ג. וּמֵעִקָּרָא לֹא נִתְקַן אֶלָּא בִּשְׁבִיל אוֹרְחִים דְּאָכְלֵי וְשָׁתֵי בְּבֵי כְּנִישְׁתָּא, לְהוֹצִיאָם י"ח, וְעַכְשָׁו אַף עַל גַּב דְּלָא אָכְלֵי אוֹרְחִים בְּבֵי כְּנִישְׁתָּא לֹא בָּטְלָה הַתַּקָּנָה, זֶהוּ טַעַם הַמְּקוֹמוֹת שֶׁנָּהֲגוּ לְקַדֵּשׁ בְּבֵית הַכְּנֶסֶת. אֲבָל יוֹתֵר טוֹב לְהַנְהִיג שֶׁלֹּא לְקַדֵּשׁ בְּבֵית הַכְּנֶסֶת, וְכֵן מִנְהַג אֶרֶץ יִשְׂרָאֵל. הַגָּה: וְנָהֲגוּ לַעֲמֹד בְּשָׁעָה שֶׁמְּקַדְּשִׁין בְּבֵית הַכְּנֶסֶת.
1 Laws of kiddush in the synagogue. Containing 1 paragraph It is the custom to recite Kiddush in the synagogue. The one who recites should not taste the wine of Kiddush but gives it to a minor to taste because Kiddush should be recited only at the place where the meal is eaten. From the outset this was ordained only for the sake of [communal] guests who eat and drink in the synagogue, so that they may fulfill their obligation. And today, even though [communal] guests do not eat and drink in the synagogue, the ordinance is not void. That is the reason of those places who still recite Kiddush in the synagogue. But it is better to ordain NOT to recite Kiddush in the synagogue, and such is the custom in the Land of Israel. Rema: It is the custom to stand when reciting Kiddush in the synagogue.