Parents Mortgage Paid off, charge remaining but bank has closed. Advice please

Hello, i am hoping someone may be able to help me.
My parents paid their mortgage off in 1997 - the mortgage was with the Portman Mortgage Services Ltd who merged with Nationwide in approx 2007.
My father has since passed away and my mother in incapacitated due to dementia.   I am trying to sell her house as its required for her care.  We have a buyer and are ready to proceed but now there is a charge showing on the Title Register.
My solicitor has contacted Nationwide who are extremely slow in responding as the mortgage was never with them and paid off before they merged.
Could anyone give me some advice please on how to get this charge removed if the original lender no longer exists and the mortgage was paid off?
It is putting the house sale at risk.
Thankyou.

Hello Jane - it reads as if you are doing all the right things re NBS and trying to resolve matters. If the original creditor merged with NBS then the latter will need to discharge the legal charge for you. Normally provided they have the specific account number and details that can be achieved although it can take time
Can you share the title number for me to check and dig a little deeper perhaps?

Hi Adam,
Thank you for responding.  NBS have responded but very slowly and said it would take time, unfortunately i think it may mean we lose the buyer.
The title number is MX31735.
Thank you for checking further!

Hi Helen Jane - many thanks. I'll see if I can dig anything up
MX31735

Hi Adam,
Not sure if you have managed to find out anymore info on this.  My solicitor has had a response from NBS which states:

'Portman Mortgage Services Limited is not an active company. The address for Portman Mortgage services would be shown as Portman House as that what is was at the time, the merger between Portman Building Society and Nationwide took place in 2007. As the mortgage was redeemed in 1996, some years before the merger it would not have come over to us. In which case the beneficiary of the charge would now be the Crown.'

Can you advise at all on what that means and how to get it removed?
Many Thanks

 

Helen Jane - my contact at NBS was investigating but as you've received a response it seems there is nothing more for NBS to offer here
The original lender was PMSL and NBS are essentially saying that they did not merge with NBS. That was Portman Building Society. 
As the company is no more it's assets can effectively pass to the crown to deal with. See our PG 35 section 7 for guidance - Corporate insolvency (PG35) - GOV.UK
You are likely to need to contact Bona Vacantia - GOV.UK for assistance with regards proving the charge was paid off/to secure the appropriate discharge