A person who freed a slave had to pay as a tax 5% of the value of the slave. The values mentioned in The Satyricon ranged from 200 to 2000; unfortunately, the monetary unit is not mentioned, but is most likely to be the silver sesterce or the denarius.

It was very common for slaves to be freed upon the deaths of their masters, although only a percentage (30%, I believe) of the household could be manumitted.

Slaves, when freed, sometimes took as part of their last name the name of their former master. For example, Trimalchio Maecenatianus had as a former patron Maecenas.

Newly-freed ex-slaves wore a freedman's cap, probably not only to symbolize their new freedom, but also to let their contacts know about their new status. No mention is made of how long the cap was worn, but it was probably a week to a month—long enough to let most people know of the change in status.