See an accountant. Tomorrow. Or sooner if possible.
Pension contributions from a company are an allowable business expense. They come off the 'profit' before any corporation tax. You can dump up to £40K of profit into her pension plan per year tax free, and carry forward the past 3 years allowance too. So she could extract up to £160K of profit from the company into her pension scheme tax free. There is no cheaper way to extract money from the company, or fund her retirement.
To be fair, I wasn't aware of that, but while ever we aren't making my pension to £40k p.a. I think it would be better to add more to mine. My effective rate is 40%, plus some NI, hers rather less. SWMBO'S Company runs about £45k as PBT and sadly, we need all of it ATM.
I scraped my ACA tax exams, so as soon as we have any spare income, I can assure you I'll be seeking some good advice!
In simple terms. Suppose SWIMBO's company makes £1K gross profit. There are 3 (legal) ways of getting the money out of the company and into her 'pocket'.
1) Salary. Employers NI is 13.8%, Employees NI is 12% and Income tax is 20%. So once all that is paid, from the original £1000 she only gets about £620 in her pocket.
2) Dividends. Corporation tax is 20%, and personal dividend tax is 7.5%. Once that is paid, she gets £740 in her pocket.
3) Pension. No taxes - all £1000 can go straight into the pension.
It's a bit more complicated than that since NI, Income Tax and Dividend Tax have various allowances and limits, but that's the jist of it.
What about using an MVL and claiming entrepreneur allowance?
And 3 misses the point that normally 75% of the fund is drawn and taxed as income. So taking that into account if you could use the MVL and entrepreneur allowance that might be better