Questions to multiple departments are sometimes called ‘round robin’ questions. Many of them will have been asked before. You should first check in the questions database or parliamentary search to see whether any other MP has tabled a similar question, or whether the information you seek is published in departmental reports and accounts.
If you are using the online MemberHub, submit the question to the first department, then find that question in the list of questions you have submitted, click ‘actions’ and ‘submit to another answering body’. Choose the additional department you want to ask.
If you are submitting your question on paper, you should provide just one copy of the question, along with a list of the departments and answering bodies you wish to ask. If you want to prioritise particular departments for named day answer, you should make that clear.
Avoid asking for "all departments". The Table Office need to be clear whether you intend to include smaller answering bodies which have very limited remits (such as the Church Commissioners). Many questions will not apply to them.