OK I have waited a bit for other contributions
I cannot - I CANNOT agree with retrochics advice ( bad advice see below) as one of my relations has been investigated for tax fraud and I can tell you it is such a pain in the ass - really just dont go there ! ( it cost £10k to defend, tax not paid £1200 ).
well if it is IHT you are referring to:
look at this: it is a form your executors fill out and page one left column is the dreaded £3000 limit
http://www.hmrc.gov.uk/cto/forms/iht205-2011.pdf
right.... here is the tax man's document on gifts
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/323687/hs295.pdf
This doc is mostly about transferring shares and houses - rollover relief.
You have specifically defined money in your post
Half way down page one it gives the advice on IHT as a clickable link
which is this
http://www.hmrc.gov.uk/manuals/ihtmanual/index.htm
which gives a pretty depressing list....
but you need this
http://www.hmrc.gov.uk/manuals/ihtmanual/IHTM14131.htm
actually it looks quite fun
I will have to have a re-read myself
In the last five mnutes I tried to find a simpler one
by googling 'IHT gifts out of income'
and it has taken my straight back to the IHT tax manual above
IHT exemptions are basically as I have said above