Potential energy surfaces are presented for the three lowest lying singlet electronic states of HOBr. The surfaces are computed using the recently developed multireference averaged quadratic coupled clusters method and a TZ2P orbital basis set. They provide the basic data needed to compute the dynamics of the HOBr + h nu --> OH + Br photodissociation process, which plays a key role in the bromine chemistry of the stratosphere. A pseudopotential is used for the core electrons of the Br atom; this is shown not to introduce any errors in the shape of the surfaces through direct comparison with sample all-electron calculations. Transition dipole moment surfaces for the two excitation processes (1 (1)A " <-- (X) over tilde (1)A' and 2 (1)A' <-- (X) over tilde (1)A') are also presented. These are computed using a multireference singles and doubles configuration interaction method. A grid based method is developed to compute the vibrational-rotational states of the molecule and spectroscopic constants extracted from the computed molecular energy level spacings are compared with experimentally determined quantities.