Difference between regular and lumpsum contributions from salary

[Deleted User]

My employer allows us to change pension contributions around Feb / Mar as it times with bonus payout. I am a higher rate tax payer.
Is there a difference between (a) regular monthly pension contribution of say 15% and (b) lower monthly contribution initially of 10% and increasing it to 25% in the last 3 months?
Am i correct in saying if my monthly income falls below 4167 (50k / 12), i'll be saving NI at 12% while also saving 40% on my income tax?

ratechaser

If it falls below the 50k threshold, than any further contributions made through a sacrifice arrangement would save you 12% NI but only 20% tax - unless that is you have a reduced/negative personal allowance reflected in your tax code which means you would be paying 40% below the 50k income mark.

eskbanker

The subject of scheduling pension contributions to optimise NI savings was mentioned in another thread last month:

https://forums.moneysavingexpert.com/discussion/comment/77193382/#Comment_77193382

Bemma

Yes, you can save 12% NI and 40% income tax at the same time as outlined in the link mentioned above.  
Avoid SS in your bonus month, only make the minimum required for employer matched contributions as you will get a large amount that month and most of it will be in the 2% NI bracket.  To be optimum, SS as much as you can, compressed into as few months as you can.  This will maximise the 12% NI gain, as the all the money you drop below £4167 per month, gains you 12% NI, even if you annual salary is above £50k.
(National minimum wage limits still apply per month for SS).

jamesd

The second way will save you more NI, getting you some 12% saving on income taxed at 40%. Income tax is worked annually while NI is calculated for each pay period.