Number 0870 070 0191 is potentially valid
Ofcom records show that numbers starting 0870070 are allocated to Vodafone Uk Ltd. Note that due to number portability if an individual number has moved to a different operator this information is not publicly available.
Ofcom's last recorded change for this number range was August 1996.
The correct way to write the telephone number 08700700191 is 0870 070 0191
For more information on tariffs and usage of numbers starting 08 please visit the page on 08 numbers