Pay in to NI Pension or SIPP

Markdavid1962

Just asking for some advice and confirmation -on a few points. I should start by saying I will retire in 4 years and we are in a good position but am now looking to see if I can improve my wifes pension.
My wife does not work and will not work again due to disability, she does have 13 years of NI contributions built up (up to 2013/14) and has 17 years until retirement
Considering the options for my wife Pay voluntary national Insurance, SIPP or a combination
As she does not pay tax would she receive the 20% tax relief on a SIPP ? (assuming she does)
Option 1
I am debating if to purchase voluntary contributions to bring her up to date (ie paying in for 6 years), makes a difference on her pension from £77 per week to £101 per week and then pay the voluntary contributions on direct debit for the next 5 years until I retire. (again will increase the per week amount)
So if I pay into the NI Pension (£4000 voluntary now) and then around £750-£780 per year for the next 5 years (another £3750 approx)
Option 2
Open a SIPP in my wifes name  and pay in the £4000 (with 20% Tax relief = £4800 and then make the same NI payments or higher( £750-780 pa) in to the SIPP for 5 years plus the 20% Tax relief. 
Option 3 
Pay the last 6 years in to the NI voluntary  as you can only pay Voluntary Contributions for the previous 6 years and then open a SIPP with the monthly amount (£200pm) going forward and at age 55 (in five years)  take the 25% Tax free lump sum from the SIPP and purchase additional NI years (going back 5 years).
£200 per month with Tax relief = 240 *12 =2880 per year (x 5 years) =14400 (25% Tax Free=3600) which is 4 years of NI contributions plus I still have the remainder of the SIPP
I am leaning towards option 3 but wanted to check the logic and approach
Thanks

molerat

As she does not pay tax would she receive the 20% tax relief on a SIPP ? (assuming she does)

Yes she would

Pay the last 6 years in to the NI voluntary  as you can only pay Voluntary Contributions for the previous 6 years

She can currently pay back as far as 2006-07

Open a SIPP in my wifes name  and pay in the £4000 (with 20% Tax relief = £4800

If she has no relevant income then she is limited to £3600 per year - £2880 + £720 tax credit

Markdavid1962

Thanks, is the 2880 + 720 tax credit a fixed figure as she does not claim tax credit or any unemployment  benefits, I guess the other option would be to put it in my name as a HR tax payer  - the relief would be higher

xylophone

Your wife has no "relevant earnings" - she can contribute a net £2880 to a SIPP and receive tax relief of £720.
https://www.gov.uk/hmrc-internal-manuals/pensions-tax-manual/ptm044100

My wife does not work and will not work again due to disability, 

https://www.gov.uk/employment-support-allowance/eligibility 

She is not on ESA but does she satisfy the conditions for it?

Linton

Paying voluntary NI when you will not earn the full SP is much more lucrative than contributing the same money to a SIPP. 1years NI contribution is repaid in extra SP in 3-4 years.

nigelbb

Each year of voluntary NI contributions at around £750 buys a pension of about £250/year. Average life expectancy at retirement is 20 years or more so overall it's worth over £5K.  

JGB1955

I've been doing both...buying extra years of NI contributions AND  investing £2,880 in a Hargreaves Lansdown SIPP. The £720 tax relief almost covers the NI contributions, so an extra £250 annual pension at negligible cost.