A SIPP is something you setup completely separate to your employment. In fact you don't even need to be employed to open one.
An American 401k is a more like what we'd call a "workplace pension" here in the UK, which nowadays is always a defined contribution scheme from a third party provider selected by your employer. These vary in fees, fund selection etc, but you usually get additional contributions from your employer, as well as better tax relief, for using it vs a SIPP.
Most employers won't pay monthly contributions from salary in to a SIPP due to the increased payroll and and admin costs, although some will do so for annual bonuses.
Confusingly there's also something that people call a "full SIPP", which is a much more expensive but less-retaily SIPP that can be used to invest in things like leveraged commercial property.
> Confusingly there's also something that people call a "full SIPP", which is a much more expensive but less-retaily SIPP that can be used to invest in things like leveraged commercial property.
If REITS are what you're referring to then I'm fairly certain a full SIPP is more analogous to a 401k. You can open a 401k today, on your own, without a business. They're just optimized for pre-tax so it makes sense that they're tied to work. Employer matching varies wildly. There is no predefined contribution that can be made by vendors, I believe the 401k limits are all federally mandated, but that mostly has to do with tax optimization.
An American 401k is a more like what we'd call a "workplace pension" here in the UK, which nowadays is always a defined contribution scheme from a third party provider selected by your employer. These vary in fees, fund selection etc, but you usually get additional contributions from your employer, as well as better tax relief, for using it vs a SIPP.
Most employers won't pay monthly contributions from salary in to a SIPP due to the increased payroll and and admin costs, although some will do so for annual bonuses.
Confusingly there's also something that people call a "full SIPP", which is a much more expensive but less-retaily SIPP that can be used to invest in things like leveraged commercial property.