מקום תפילין של ראש

Anybody who ever learned hilchos tefillin knows that the shel rosh must be completely above the hairline. If one centimeter of the shel rosh is beneath the hairline then it is as if he is not wearing tefillin. This is the psak of the Taz and Mishna Brura [simman 27] and many other achronim.

Problem: Go to your local shul and see how many people have their tefillin hanging BELOW their hairline. This has been troubling me for years. In addition there have been great tzaddikim [see here] whose tefillin was below their hairline [but see here - he brings no source and I find that hard to believe. In general one should avoid those superficial text message teshuvas]. Are all of these Jews not wearing tefillin???

There are tshuvos about this in the Dvar Yehoshua [R' Yehoshua Ehrenberg 4/11], Machshavos Bieitza [simman aleph] and Berurei Halachos [R' Mordechai Eisenberger simman heh] where justification is found for this seemingly errant custom.

1] The Heilige Klausenberger was asked about this and replied איך האלט אז דער פלאטץ ביים קאפ וואס איז שיף גיעהערט צום גובה הראש אין איז נישט אין חלק פין מצח - I hold that the place where the head slopes down is still called "gova harosh" [where the tefillin must be placed] and is not considered part of the forehead. In other words there are some people with high foreheads and their hair starts growing higher up than normal. Such people's foreheads halachically doesn't start until a little bit lower down than where their hair starts growing. Hence, they may place their tefillin lower than their hairline.

2] Roobo Kikoolo: As long as most of the tefillin is above the hairline its ok. [Question: When do we say roobo kikoolo and when not? Can one eat most of a kezais matza on pesach and be yotzei?? Clearly not! Is one obligated in mitzvos at the age of 7 since he has reached the majority of years towards bar mitzva? Clearly not! Can a woman cover the majority of her hair and leave the rest uncovered? No sir! [Or ma'am!] But one may shecht most of the simmanim of an animal and that suffices! So what determines when we require koolo kipshuto?]

3] Some of the tefillin doesn't actually touch the head but hangs in the air. As long as what actually touches the head is above the hairline that suffices.

My advice - stick with the psak of the mishna brura and make sure that everything is above the hairline but BARUCH HASHEM we have a limmud zchus for those who don't.