Thanks for your question
I am afraid you will be liable to capital gains consideration whether you invest in another property or not.
But assuming you have declared all the rental income to HMRC - you are due private residence relief for the time you lived there and the last 18 months of ownership
So you owned the property (so far) for 105 months and lived there for 46 months - so 46 months plus last 18 months of ownership allow 64 months with private residence relief.
£19,000 gain x 64/105 = £11580 exempt for private residence relief (PPR) and leaves £7420 gain
So then private lettings relief is due (assuming you declared all rental income to HMRC) and this is the lesser of
1) the amount of gain on which PPR is due - so £11580
2) The amount of gain left over after PPR has been applied - so £7420
As the lesser amount is 2) the amount iof gain left over after PPR has been applied - so £7420
Deducted from the reminign gain of £7420 - leaves NIL capital gains to tax.
But I will add even without the private lettings relief ,as the gain was only £7420 and your annual exemption allowance is £11,000 then you still have no taxable gain!
So NIL to pay - you can bank all of the £19,000 tax free. Just ensure you alert HMRC of the sale.
Thanks for your response
If you already complete self assessment (which I suspect you do - as you are in receipt of ental income) then you just need to add in the capital gains tax section of the 2015 return (if the sale takes place before 05/04/2015)
If you do not complete self assessment tax returns - then you can either telephone and ask them to set you up for a self assessment tax return for the year OR fill in an online request for self assessment - link here
The reason you have to declare this sale is because your NIL position is first and foremost due to your entitlement to private lettings relief - and HMRC need to be aware of how the gain has been calculated and how the tax reliefs have been applied)
If you wish a more accurate calcualtion once the sale has taken place, do come back to Just Answer, and you can always ask for me Sam Tax - and if another expert interjects (as the lock of any newly posted question releases afetr 15 minutes) just advise you would like to wait for me - as I am online every day.
Let me know if you have any follow up questions, but in the meantime, it would be much appreciated if you could rate (or accept) the answers I have provided, as this ensures that Just Answer credit me for my time