One ledger per licence, always
Every company or establishment with its own licence keeps its own ledger, bank account and invoice numbering. Do not run two licences through one set of books with a tag for each. Authorities, auditors and banks will ask for each entity’s accounts separately, and untangling a combined ledger later is slow.
Where one owner holds several sole establishments, the legal picture differs from companies, because the owner is the same person. Ask your tax agent how the businesses should be registered for VAT and corporate tax, but keep the books separate anyway. It is the only way to know which business makes money.