Submitting expenses through Slack offers the fastest, most convenient method for employees. Send receipts to the Light bot without leaving Slack, review the extracted data, and get reimbursement statu...
Last updated Jul 22, 2026 · 4 min read
There is no per-channel configuration. Light matches each Slack user to their Light account by email address — the email on your Slack profile must match the email on your Light user. The bot then works with you through direct messages.
To submit expenses via Slack you need:
If either is missing, the bot replies telling you what to fix (for example, "You are not set up for reimbursements") and to contact your admin if needed.
Supported file types include PDF and common image formats (JPEG, PNG, HEIC, TIFF). Files above the maximum file size are rejected with a message telling you the limit.
Note: If you are also a cardholder, Light first tries to match the receipt to a card transaction. If no transaction matches, the bot asks "Do you want to create a reimbursement from this item?" with Reimbursement and Discard buttons — click Reimbursement to create an expense.
After processing, Light sends you a message:
"Here's what I got from the receipt:"
The message shows:
The expense is created as a draft. To correct any details (description, amount, date, category), open the page in the Light web app and edit the draft there.
If extraction fails, Light tells you "There was an issue extracting the details from the receipt" and asks you to go to the web app to fill out the missing details — best done on a computer.
Draft expenses are grouped into an expense report (reimbursement). Once you are done uploading all of your receipts, you can either:
Submitting sends the report for review through your company's approval workflow.
Light sends these status updates as Slack DMs:
Ask the Light bot directly — there are no special commands. In a DM, ask in natural language, for example:
The bot answers using your data in Light. You can also mention @Light in a channel it has been added to and it replies in a thread.
Submit multiple expenses at once:
For best AI extraction results:
If Light couldn't read the receipt, it sends: "There was an issue extracting the details from the receipt." The receipt is still uploaded — go to the page in the web app to fill out the missing details manually.
If a file fails validation, Light replies explaining the problem:
Fix the file (or take a new photo) and resend the message with valid files.
If the bot replies that it could not find an active user with your Slack credentials, your Slack email doesn't match a Light account. Ask your admin to check your Light user's email address.
Open the draft expense on the page and correct the details before submitting your expense report.
The Light bot doesn't use slash commands — it understands natural language:
Your expense submissions in Slack:
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