If you run a small company and an accountant does the books, the bookkeeping is not really your job, but the gathering still is, and most people are never given a list of what the gathering consists of. You work it out from the questions that come back.
This is that list, written out. It is the same whether you send a shared folder, a zip file or a stack of attachments, and it holds whether or not you use any software to assemble it.
Six kinds of thing, and you only send the ones that apply to you. A company with no card has no card statement, and a company that takes no online payments has no payout report.
This is the one procedural thing that changes how long the whole job takes. Open the statement, go down it line by line, and for each line find the document that belongs to it. The statement is the spine and everything else attaches to it.
Doing it the other way round, starting from the pile of receipts and filing each one somewhere, feels like progress and leaves you with no way of knowing when you are finished, because nothing tells you which payments you have not covered yet. It also produces duplicates: an invoice you received and the payment that settled it are one event, and if you file both as separate entries the month adds up to more than you actually spent. The invoice belongs to the payment.
The same goes for a payment that appears twice because it crossed currencies, or because it shows up in both a card statement and the bank account it settles into.
Some lines have nothing behind them and never will. Bank charges, card fees, interest, and transfers between two accounts the company owns are all real movements with no invoice attached to them, and the statement itself is the document in those cases.
Write that on the line rather than leaving it empty. An accountant reading a blank cannot tell whether the document is missing or does not exist, so a blank generates an email and a note saying "internal transfer to the savings account" does not. The same applies to a receipt you genuinely cannot find: saying it is lost is a smaller problem than saying nothing, and it lets them decide what to do about it in the same pass rather than after asking you.
A handover usually stalls on a handful of items where the paperwork is complete and somebody still has to make a call. The lunch that might have been a client meeting or might have been lunch. The hardware bought on the company card and used at home half the time. The subscription in your own name that the company actually pays for.
Your accountant cannot answer any of those, which is why they come back to you as questions, and the questions arrive after they have started work rather than before. Deciding them while you assemble the month, and writing the decision down next to the line, removes most of the back and forth. You do not have to be right in any deep sense; you have to have said what you think, so that they can tell you if it is wrong.
Then this list is the wrong shape for you. Everything above is about handing a period to somebody who then does the double-entry, the VAT return and the filing. If you do all of that yourself, what you want is bookkeeping software, and there is plenty of it that is good.
Clerk.AI does this gathering for you on your Mac. It signs into the banks and the billing portals, pulls the statements, hunts the matching receipts through your email, works down the statement line by line the way this page describes, and asks you about the handful of things it cannot settle on its own. What your accountant gets is a folder and a drafted email.
The checklist above is worth having either way, and you are welcome to take it and do the month by hand.
Runs on your Mac. Pay what you decide, including nothing.