Pay large sum off mortgage now v waiting till May?

Not sure if this is the right place for this query - please move if appropriate.

Being made redundant shortly. Lumpsum will be approx 75% of outstanding mortgage. SSIAs due next May expected to be roughly the remaining 25%.

I want to put the lump-sum against the mortgage right away, reschedule the payments (since we will be living on a single income), and then in May, use the SSIAs to clear the remaining debt.

Mr 3Dolls is leaning towards putting the redundo into a high-yield a/c until the SSIAs mature, then clearing the lot in one go.

We have no other loans, credit cards cleared monthly. I don't see any financial sense in his suggestion - We're very unlikely to get a higher rate on savings than we're paying on the mortgage (think it's 4.5% - NIB Tracker II) so we'd be paying a certain amount of interest unnecessarily for 5 months.

Can anyone think of any reason why we should wait till May to pay the whole lot off? Maybe there's an angle I'm missing.

I'd lump it off the mortgage ASAP before the rate goes up again. It might only add 3 quid to the balance (unlikely!) but I'd begrudge them that 3 quid... good luck post-redundo!

For the sake of six months I doubt it's worth putting the money into a savings account.

My advice would be to pay off the mortgage or consider investing it into something longer term.