A man has been charged in connection with the investigation into the so-called "Punish A Muslim Day" letters, West Yorkshire Police said.
David Parnham, 35, is accused of 14 offences including one count of soliciting to murder.
Read more: Counter-terror police get more time to question 'Punish a Muslim Day' letters suspect
He is also charged with two counts of sending a number of letters promoting a "Punish A Muslim Day", encouraging the commission of one or more of a number of offences.
Parnham faces a further five counts of sending a substance with the intention of inducing in a person a belief that it is likely to contain a noxious substance, five counts of sending a number of letters conveying a threat and one count of making a bomb hoax.
The man, from south Lincoln, is due to appear at Westminster Magistrates' Court this morning.
Parnham was arrested on Tuesday by counter-terrorism police as part of an intelligence operation.
A residential property and office building in Lincoln city centre were searched.