A SIPP is a self-invested personal pension plan. By switching to a SIPP you gain control over how and where your pension funds are invested. This is different to a SSAS. A SSAS is a small self-administered scheme pension. Whilst a SIPP is a personal pension, a SSAS is a corporate pension. A SSAS is only available to company directors and a SSAS can have up to 11 additional members. A SIPP is just a personal pension. Both a SIPP and a SSAS can invest in commercial property. With both the SIPP and the SSAS, it is important to take expert advice when investing to ensure that you adhere to rules. A SIPP and a SSAS are vehicles for consolidating old frozen or dorman pensions.