NOTES ON SURNAMES (HULL) 11
COULTAS Reaney explains this Yorkshire surname as meaning “Worker at the colt house, colt keeper”. He cites notices of freemen of York with this name, variously spelt, between 1562 and 1733. I would add Edward Coltus, glover, in Hull, 1528. Also it is worth noting that Colt House is a place-name of North Yorkshire (old West Riding), near Ripon.
Richard Coutas (sic), Duggleby, East Riding, 1623; Elizabeth Coultus married Lyonel Catlin at Holy Trinity, Hull, 1633; Joseph Coultas and family were assessed for tax in Hull, 1695.
Eleanor M. Reader (“Broomfleet and Faxfleet”, 1972, p.34) mentions an 18th century Broomfleet family, originally Coltas, which had become Coultish by 1790.