Thanks for your response and the additional information
Then as you have been abroad (be in though in the UK from Guernsey ) then the time you lived there plus 4 years plus the last 18 months/ total period of ownership will form an exemption (so in essence gain x 126 months/ 300 months
Plus you will be eligible for private lettings relief which allows up a furtehr exemption of £40,000 max
Then if the property is in joint names you each have an annual exemption of £11,100 and then if any chargeable gain remains, this will be liable to capital gains tax.
BUT IF you return to the property even just to sell - then the whole gain will be exempt as you live din job related accommodation for your work - so this is certainly worth considering to avoid any charge at all.
There is sometimes scope for you to be treated as fully exempt under these conditions of job related accommodation when you do not return to the property but this isi when an individual is relocated due to work (and not retirement) and therefore cannot take up the geographical located property.
Then resume life in the UK with perhaps a property purcahse along with the sale - or the ability to take your time with a purcahse at your leisure!
Let me know if I can assist further - or if you have all that need then it would be appreciated if you could rate me for the level of service I have provided (or click accept)