On Alfie's tag I have my surname, my mobile number, my house phone number and that he is chipped. My address wouldn't fit on it and I didn't put his name on it because I think it would be easier for someone else to claim ownership if they knew the name the dog responded to. I figure if he ever goes missing I'll be out frantically searching for him so the mobile number is probably the most useful one.
Myself and OH have different surnames too as we're not married but mine is shorter and easier (he's Polish and his is impossible!
) so we agreed to use my name on all stuff to do with Alfie - his tags, insurance, KC reg, vet records, microchip records etc. just for consistency... plus if it ever goes Pete Tong with OH then Alfie is mine!!