On 8 Nov, 17:01, Man at B&Q wrote:

Re-mortgaging was a *bad* move.

You need to get a BTL mortgage on the rental property ASAP. Otherwise
you are not allowed to offset the interest payments against rental and
will be taxed on the full value of the rental payments. Having a
mortgage on the BTL property is like borrowing money to run a
business. If you remortgage your home, you are deemed to be using your
own capital rather than a loan.

Did you take any advice before starting down this road?

I hate to have to say you're wrong, but you are! The test for whether
the mortgage interest is a deductible expense is what the PURPOSE of
the loan was (to buy a rental property), not what the loan is secured
over (or indeed whether it's secured at all) or whether it's marketed
as a BTL mortgage. If in doubt check the Inland Revenue document on
this.

Anyway, my understanding of the original post what that he has only
raised the deposit through the remortgage, the bulk of the money will
be raised through a loan secured over the place to be let out. All the
interest on all the money he borrows to buy the property (via both
loans) is deductible (as are loan interest payments for any business).