Do the maths on how many days a month you genuinely need before you commit. If it's occasional or unpredictable, pay-as-you-go day offices win, because you only pay when you turn up. If it's frequent and fixed, a serviced office, which is a private office on a monthly contract with reception, cleaning and meeting-room access, can work out better value. A coworking membership, regular hot desks or ad hoc meeting room hire sit in the middle for something in between. If your regular need is mostly meetings, it's worth looking at
options for conference and meeting rooms.
One thing to flag on business addresses.
GOV.UK states that a company's registered office must be an appropriate address where post comes to the attention of someone acting for the company. A one-off day booking won't serve as a registered office, but some serviced-office providers offer a formal registered-office service that does.