England, United Grand Lodge of England Freemason Membership Registers, 1751-1921 which has 1,713,246 entries
Ireland, Grand Lodge of Freemasons of Ireland Membership Registers, 1733-1923 containing 318,964 entries.
The collections are name indexed with images of the original registers linked. Registers vary but typically list name, a date or dates for an event or events, a record of dates of continuing membership and "observations," which can include a date of death. They may also note the dates a man advanced through the degrees of Freemasonry, and from the latter part of the 19th Century, professions.
Men in business were often Masons.
This collection is worth searching on the off chance. I was surprised to find in the English collection a family member who subsequently "did a run." His occupation and address are in the register. In the Irish collection I found a man with a somewhat uncommon family surname in New Brunswick in 1848.
For more on Freemasonry in England today see www.ugle.org.uk/what-is-freemasonry