Had a bit of a nightmare on Saturday morning as couldn't get a taxi from a house that we were at. Tried everybody in our phone books. But after about an hour we phoned Ace taxis which were prompt & sent us out 2 swiftly.
There number is 0114 273 74 75
Other taxis that I use are RD Taxis on 0114 2466 466 or 0114 2464646
Other taxi numbers are
Unfortuantly can't remember the names but they were under my phone from calling them on Saturday morning. Taxis also depend on what area of sheffield that your in. If you have a taxi office near you then they are probably the best bet to have cars in your area.