1,702. Invalid Signatories
Hilchos Geirushin 1:17
If one or both of the witnesses who signed the get are invalid, then the get is ineffective even if the man delivered it to his wife in front of two valid witnesses. This get cannot be used because it’s like a forgery.
Hilchos Geirushin 1:18
If the witnesses signed the get more than two lines’ distance from the text, it is invalid. The witnesses must sign within two lines’ distance so that their names will be read with the get’s text. The exclusion in the first sentence of this halacha applies when the get is already in the woman’s possession and there are no witnesses that it was delivered; if the man delivered it in front of witnesses, then the get is valid even if the witnesses’ signatures are far away from the text of the get. This is true even if no witnesses signed the get at all because, as stated, divorce is ultimately effected by the witnesses to the get’s delivery.