Reasonable funeral expenses are recoverable from the deceased’s estate, on which they have first claim.
The person who makes arrangements with a funeral director makes him or herself responsible for paying the bill. A funeral director will be reluctant to enter into a contract if he or she is aware of family disagreements. Having entered into a contract, a funeral director has every right to answer directly to the contractee and no one else.
Claimants of means-tested benefits and tax credits may be eligible for a contribution to funeral expenses from the Social Fund. See here.