That's a good summary of the two separate issues under discussion Brendan.
1) Should the OP use his lump sum to pay off his mortgage. I think that the answer here is absolutely clear and agreed by most people
Agreed (although I would suggest holding back a liquid cash reserve equivalent to 6 months' household expenses to address emergencies).
2) Should someone make pension contributions if they are getting only 20% tax relief?
This is discussed at length here:
Pay down your SVR mortgage before starting a pension, but don't leave it too late
It seems to me that someone should not borrow at 3.5% to tie their money up in a pension for 29 years. If you make a lot of assumptions, and these assumptions turn out to be true over 29 years, it may work out right. But there are many changes which might happen over 29 years, and you will be kicking yourself that you spent money like this
It seems to me that the only significant assumptions you need to make are that (1) the annualised rate of return on the pension fund will at least match the interest rate on the mortgage over the 29 years; and (2) that the tax treatment of pensions and mortgage interest payments will not change over that time period to the point that it materially impacts this analysis.
I would have thought that it is much more likely than not that the rate of return on the pension fund will materially exceed the mortgage rate over that time frame, particularly when you bear in mind that the pension fund will have a 20% "head start" due to the tax relief on contributions.
It is obviously impossible to predict with any accuracy what politicians might do in the distant future but I would have thought that it is fairly unlikely that the tax treatment of pensions and mortgage interest payments will change so materially over that period that it fundamentally changes this analysis.
1) You earn income which puts you in the top tax rate, but you no longer have the spare income to put into your pension.
Well, if the OP follows the advice at 1. above he will have a very modest mortgage and if he earns income at the top rate he will obviously have additional income from which he can continue to make the maximise his annual pension contributions.
2) The tax relief changes so that everyone gets tax relief on pension contributions at 30%.
Would that not be an argument in favour of a standard rate taxpayer maximising his annual pension contributions?
3) In 29 years, all pensions might be means tested. If you have a big private pension, then you might get no state pension.
It's certainly possible (although I think it's unlikely) that the contributory OAP will disappear completely so that we are just left with the means tested OAP. But surely that's an argument against making pension contributions (or even saving for retirement outside a pension vehicle) in any circumstances? Also, I don't think you can safely assume that a paid for home would always be excluded from a means test calculation.
4) Interest rates rise significantly - you will wish you had a lower mortgage
If interest rates rise significantly, it is highly likely that the return on the pension fund will also rise significantly (albeit with a time lag).
5) The lower your mortgage, the lower your LTV, the lower the interest rate you will pay. Although, if you are below 50% LTV, you probably won't get it any cheaper
Again, if the OP follows the advice at 1. above his mortgage will be well below 50% LTV.
6) You might want to trade up within the next 20 years, and money tied up in a pension will be of no use to you.
True but the OP will presumably have significant equity in his house if he wants to trade up and will still need to fund his retirement in any event.
But,on balance, it's just wrong to borrow money at 3.5% to tie up your money for 29 years for tax relief at 20%. It's probably ok to do it at 40%. But with 29 years to go, I would not be convinced.
I absolutely agree that it's a question of balance but, in the OP's specific circumstances, I would come to the opposite conclusion on this issue.
If, for the sake of argument, the OP had a mortgage free house (or had a modest home loan on a tracker rate) would you still take the view that a standard rate taxpayer should never make pension contributions?
I also think it's worth making the points again that (1) there is an annual limit on how much can be contributed to a pension and this annual allowance cannot be carried forward; (2) the OP would lose his employer's match on his contributions.