Number 070 5383 6814 is potentially valid
Ofcom records show that numbers starting 070538 are allocated to Simwood eSMS Limited. 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 July 2006.
The correct way to write the telephone number 07053836814 is 070 5383 6814
For more information on tariffs and usage of numbers starting 07 please visit the page on 07 numbers