PIBS are Permanent Interest Bearing Securities. These have been issued by many UK Building Societies and are a class of subordinated debt. Coupons are fixed and the bonds have no fixed redemption date. Investors purchasing PIBS can benefit from a long stream of income flows. However, the lack of a fixed redemption date means that holders will be reliant on the market price when they wish to liquidate their investments.

Investors should be aware that PIBS are subordinated debt, and rank lower than deposits and/or senior bonds in the event of the issuer being forced into liquidation. Many PIBS also have calls, an option that allows the issuer to repurchase the bond at par at certain dates.  Thus, caution should be exercised if paying above par.