Extension of term on private mortgage

I provided my daughter with the funds to purchase a house.  A formal mortgage document was drawn up and the charge registered.  The mortgage states that the debt has to be repaid this year.  She is unable to do so and I am happy to entend the term, leaving all other terms untouched.

Do I need to register anything to extend the existing mortgage term, or can I just draw up and agreement with her to extend the term to a later date?

Thanks

Sharon - if the charge has been registered we don;t then add 'more' re the terms and conditions of repayment. So no extension or agreement is perhaps needed but it's really legal advice you need to confirm the legal position 
If you decide you do want to vary the terms of the charge you would need to enter into a legal agreement/deed to do so and again you'd need the assistance of a conveyancer to draw one up, which you could then register.

So I presume then that provided I don't apply to remove the charge from your registry, it can sit there until it is finally paid off and I then apply to remove it. 

Thanks

Sharon - correct. If you need to check and confirm how it is registered then you can do so online by viewing, downloading and saving a copy of the register for £3 and at any time
I suspect one of you already has a copy though

Thanks