Under Tier 4 restrictions in Wales, community centres, youth centres and similar may be opened to provide essential voluntary services. They are also allowed to open to provide public services at the request of a local authority or the Welsh Ministers.
Examples of services for which they might open include: blood donations, polling stations, food banks, the conduct of mass coronavirus testing or vaccinations, childcare, mental health services, organisations who support those suffering from substance misuse or addiction.
See https://gov.wales/business-closures-alert-level-4 for Welsh Government guidance.