can I swap cordless handsets?

I have a Binatone Veva 1210 twin cordless set, and handset 2 has stopped working properly. Although I can hear the caller, after a few seconds they cannot hear me. Handset 1 works fine.
Rather than buy a new set could I simply put handset 1 on the base unit for handset 2, and vice versa? I do not need to use handset 1 (there is no phone socket in the room where handset 2 is, so I can't move the base unit).
I have had the item for less than a year but unfortunately have lost the paperwork so can't return it to Argos.