You should maintain records of every person or organisation supplied with the electoral register and absent voting lists, not just those who pay to receive it.
You should ensure that every person/organisation receiving the register, whether on publication, by sale, or on request, is aware that:
they must only use the register for the purpose(s) specified in the Regulations permitting its supply
once the purpose for which the register has been supplied has expired, they must securely destroy the register
they understand penalty for misuse of the register
We have included the information suggested above in the following cover sheets for the sale and supply on request of the electoral register: