I recently contacted the HMRC via the hmrc.gov.uk website, and thought my email and the HMRC's response might be helpful to someone else as well:
I emailed:
I am an American citizen living in Scotland on a 5-year work permit. Will I be
taxed on money I transfer from my U.S. bank account into my U.K. bank account?
I want to use the funds for a deposit on a home purchase in the amount of
$20,000 US dollars/ 10,000 British Pounds Sterling. Roughly how much will my tax
be if I must pay on this amount? Thank you.
The HMRC responded:
Income Tax is a tax on income so there is no liability on the actual transfer of
funds.
Having said that, a non-domiciled UK Resident is only chargeable on overseas
interest remitted to the UK rather than the full amount arising.
So if any interest arose to the account after you became Resident here, it will
be deemed to be part of the funds transmitted here and liable to tax.
Hope this info is helpful; it's nice to give something back to UK-Yankee after gleaning so much great advice before, during, and after my move here to the UK