After the Restoration, Collins was appointed successively accountant to the excise office, accountant in chancery, and secretary to the council of plantations, exchanging the last post in 1672 for that of manager of the farthing office. With this employment went a house in Fenchurch Street, where he had thoughts of setting up a stationer's shop, and hoped 'to fall into the printing of books,' including some he himself designed to write, 'particularly one of the modern advancement of mathematical sciences, and an account of the best authors of that kind'. He did not, however, succeed in carrying the plan into effect. With the failure of his arguments against the issue of tin farthings his office ceased, and he was glad subsequently to accept a small post as accountant to the Royal Fishery Company.