How can I set up a pension funded by my employer?
First you will need open a SIPP account. You can do this online here or complete the 'Fidelity SIPP application Form'. Once set up you can complete ad-hoc contributions from your employer online - select 'Manage investments' and 'Add cash'.
If your employer is making regular payments into your SIPP then you will also need to submit a completed 'Employer Contributions Record of Payments Due Form'.