Small Self Administered Pensions (SSAS) are common for owner managed businesses.
In general a company can pay up to £40k per year into a SSAS for a employee and if the allowances haven’t been used there is 3 year carry forward option, which could mean up to £120k.
However, where a SSAS has multiple members a company could contribute £500k and get full tax relief. This known as an indirect payment.
Corporation Tax relief on the indirect contribution is available in the year it’s made. It needs to meet the “wholly and exclusively for the purpose of trade” test.
If the contribution exceeds £500,000 (up to a maximum of £2 million), the relief must be spread over future years.
Here are the HMRC rules https://www.gov.uk/hmrc-internal-manuals/pensions-tax-manual/ptm043400
Speak to you SSAS provider for advice and further details