CGT on PPR Mortgage refinanced to BTL Mortgage

I bought a house for primary private residence in 2000 on a residential mortgage. I lived in it until 2005 and transferred to a BTL mortgage and releasing £10,000 equity from the property. In that 5 yrs to 2005 the property increased in value by £10,000. I have let the property out since 2005 and the property value has only increased a further £5,000. Would I be subject to paying CGT on the full £15,000 gain in value since I've owned the property from 2000? Or just subject to paying CGT on the £5,000 gain in value since I've had a BTL mortgage from 2005? Thanks

Hi 

A capital gain is calculated with the acquisition costs deducted from the disposal value.  The methods used to acquire the property, such as BTL mortgage or releasing equity does not affect the capital gains calculation.  
Please have a look at the guidance on calculating private residence relief at HS283 (HS283 Private Residence Relief (2024)).  
There is a capital gains tax calculator at Tax when you sell property, to help you work out your gain.  
You can also register, report and pay capital gains tax from What you pay it on.

Thank you

I have a similar case. Say I sell my 2nd home (not the one where I live). On the 2nd home say I still have to pay £100000 on the Mortgage on the original value of £200000 and I sell for £200000. Is the Capital Gain calculated on the remaining balance of £100000 or the actual value? Please advice Kind regards Roberto

Hi roberto scipioni,
Your mortgage is not taken into account when working out Capital Gains Tax.
It is based on any increase in value from date bought to date sold.
Further guidance is here:
Tax when you sell property.
Thank you.