How Lumen Studio closes the month in two days

Lumen Studio is a 60-person design and engineering studio with offices in London and Lisbon. Eighteen months ago, their month-end close took eleven working days. Today it takes two. This is how they did it, without hiring anyone new.

The starting point

Lumen’s finance team of two spent the first half of every month chasing receipts, recoding transactions and rebuilding project profitability reports by hand. Client billing depended on timesheets in one tool, expenses in another and payments in a third.

• Around 30% of card transactions arrived without a receipt.

• Project costs were allocated manually at month end.

• Currency conversions between GBP and EUR were reconciled line by line.

What they changed

Receipts within 48 hours

Lumen switched every employee to a Saro card and turned on automatic receipt reminders. Anyone with receipts outstanding for more than two days gets a nudge, and after a week, their card pauses. Missing receipts dropped from 30% to under 2% within two months.

Projects as a field on every transaction

Each card transaction now asks for a project code at the moment of purchase. Saro suggests the most likely project based on the cardholder and merchant, so most people just confirm. Project costs are allocated the day they happen, not at month end.

One ledger for two currencies

Lumen holds GBP and EUR balances in Saro and pays suppliers from the matching currency. Conversions happen at the mid-market rate and are recorded automatically, so there’s nothing left to reconcile by hand.

The results

• Close time: from eleven days to two.

• Project margins: visible weekly instead of quarterly.

• Finance team time: roughly 60 hours a month freed up for planning and client billing.

“We used to find out a project had gone over budget after it was finished. Now we see it while there’s still time to do something about it.”

Advice for other studios

Lumen’s finance lead says the biggest lesson was to change habits before changing reports. Getting receipts and project codes right at the moment of purchase made every report downstream accurate by default.

• Start with the habit that causes the most work at month end. For most teams, that’s receipts.

• Make the right action the easiest one: suggestions, reminders and one-tap confirmation.

• Share the results. When the team saw project margins weekly, they started asking for them.

Next, Lumen plans to connect client invoicing to the same project codes, so every project shows revenue and cost side by side in real time.