Kiddushin 1:2-3

Kiddushin 1:2

A Jewish servant is acquired through money or a document and he acquires himself at the end of six years, upon the arrival of the Jubilee year or by paying off his remaining years of service. Female servants have an advantage over male servants in that they are also released upon showing the signs of puberty. A servant who chose to remain after his term was up and had his ear pierced is acquired (for the additional service) through the piercing and released upon the arrival of the Jubilee year or the death of his master. (Unlike other servants, those who were acquired by piercing are not inherited by the deceased’s heirs.)

Kiddushin 1:3

A Canaanite servant is acquired through money, a document or by precedent (chazakah – i.e., acting as this person’s servant). He acquires himself through others paying to free him or through a document himself; this is the opinion of Rabbi Meir. The Sages say he may even acquire himself by personally paying to free himself – specifically by using money given to him by others - or by others using a document on his behalf.