The Department for Education continues to advise against both overnight and non-overnight domestic (UK) and overseas educational visits (trips). This advice is available here: https://www.gov.uk/government/publications/coronavirus-covid-19-travel-advice-for-educational-settings/coronavirus-travel-guidance-for-educational-settings.
In the autumn term, schools can resume non-overnight domestic educational visits. Guidance is available here: https://www.gov.uk/government/publications/actions-for-schools-during-the-coronavirus-outbreak/guidance-for-full-opening-schools.
All such visits should be compliant with COVID-19 guidelines and subject to a thorough and ongoing assessment of the risks to ensure that they can be undertaken safely. Schools should consult the health and safety guidance on educational visits when considering any visit, available here: https://www.gov.uk/government/publications/health-and-safety-on-educational-visits/health-and-safety-on-educational-visits.
Schools should not resume overnight visits for the time-being. This is consistent with the latest government guidance on meeting people from outside your household, which advises that you should not stay overnight away from your home with members of more than 2 households: https://www.gov.uk/guidance/meeting-people-from-outside-your-household-from-4-july.