Financial Liabilities dercog

Sir its written in the bpp text that if a change in the financial liability’s contract is more than 10% it shud be considered as an extinguishment of the original contract and making of new one.

But if the change is only to part of the liability and it only results in a change of more than 10% to that part only not the whole liability. So will derecognise the whole liability in that case or just the part of it?