Help Center / Expense Management

Submitting Expenses via Slack

What is this page about: How to connect Light's Slack bot, submit a receipt as a direct message, review what Light extracts, submit your expense report, and check your reimbursement status, all without opening the Light app.

On this page

  • Setting up the Slack integration
  • Submitting an expense
  • Reviewing what Light extracts
  • Submitting your expense report
  • Tracking reimbursement status
  • Submitting several receipts at once
  • Getting a clean receipt photo
  • Troubleshooting
  • Talking to the Light bot directly
  • Privacy and security
  • Related Articles

Setting up the Slack integration

An admin connects Slack once for the whole company. Every employee reaches the bot through a direct message, so there is no per-channel setup.

  1. Open Settings (gear icon) and go to Integrations.
  2. Click Connect next to Slack.
  3. Complete the OAuth flow to authorise Light in your Slack workspace.
  4. The Light bot is now installed and ready for anyone in the workspace to use.

How Light matches you to your account. Light matches each Slack user to a Light account by email address. The email on your Slack profile must match the email on your Light user record.

To submit expenses via Slack, you need:

  • An active Light user with the same email address as your Slack account
  • The reimbursement role, with an active reimbursement setup in Light

If either is missing, the bot tells you what to fix (for example, "You are not set up for reimbursements") and asks you to contact your admin.

Submitting an expense

  1. Open Slack and start a direct message with the Light bot.
  2. Attach your receipt to the message and send it. You can attach several receipts to a single message.
  3. Light reacts with an hourglass while it processes the file, then a checkmark once the receipt is uploaded, or an X if something went wrong.
  4. Light's AI reads the receipt and sends you a message with what it found.

Supported file types: PDF, image files (JPEG, PNG, HEIC, HEIF, and other common image formats), plus CSV, HTML, and plain text files. If a file is over the maximum file size, Light rejects it and tells you the limit.

If you also hold a company card, Light first tries to match the receipt to a card transaction. If nothing matches, it asks "Do you want to create a reimbursement from this item?" with Reimbursement and Discard buttons. Click Reimbursement to create the expense.

Reviewing what Light extracts

Once processing finishes, Light sends you a message starting with "Here's what I got from the receipt:", showing:

  • Description: what the expense appears to be
  • Original amount: the amount and currency on the receipt
  • Reimbursement amount: that amount converted to your reimbursement currency

Light creates the expense as a draft. To correct any detail (description, amount, date, category), open the Light app's Expenses page and edit the draft there.

If Light can't read the receipt, it says "There was an issue extracting the details from the receipt" and asks you to fill in the missing details on the Expenses page in the Light app. This is easiest to do on a computer.

Submitting your expense report

Light groups your draft expenses into an expense report (a reimbursement). Once you've uploaded all your receipts, submit the report one of two ways:

  • Tell the Light bot in your DM to submit your expense report, or
  • Open the Light app's Expenses page and submit it there

Submitting sends the report into your company's approval workflow for review.

Tracking reimbursement status

Light sends status updates as Slack direct messages:

  1. Upload confirmation: "Your receipt was successfully uploaded," with the extracted details
  2. Rejection notice: "Your expense report was rejected," with the reason from your finance team and a link to reset your expenses
  3. Payment notice: "Your reimbursement has been paid," with the amount sent to your account

To check status yourself, ask the bot directly in plain language, for example:

  • "What's the status of my reimbursement?"
  • "Which of my expenses are still in draft?"

The bot answers using your data in Light.

Submitting several receipts at once

  1. In your DM with the Light bot, attach several receipt files to a single message.
  2. Send the message. Light processes each file and creates one draft expense per receipt.
  3. Once you're done uploading, submit them together as one expense report.

Getting a clean receipt photo

For the most accurate extraction:

  1. Use good lighting. Natural light works best.
  2. Capture the full receipt. Keep the entire receipt in frame, not just part of it.
  3. Photograph it flat. Avoid an angle.
  4. Focus on the receipt before you take the photo.
  5. Use recent receipts. Faded, older receipts are harder to read.

Troubleshooting

Extraction didn't work. If Light can't read the receipt, it sends "There was an issue extracting the details from the receipt." The receipt is still uploaded. Go to the Light app's Expenses page to fill out the missing details manually.

File was rejected. Light explains why: the file is over the maximum size, or the file type isn't supported. Fix the file, or take a new photo, and resend it.

Bot doesn't recognise you. If Light replies that it can't find an active user with your Slack credentials, your Slack email doesn't match a Light account. Ask your admin to check the email address on your Light user.

Wrong details extracted. Open the draft expense on the Light app's Expenses page and correct the details before submitting your expense report.

Talking to the Light bot directly

The Light bot understands plain language rather than slash commands.

  • Direct messages: ask about your expenses, policies, or company data.
  • Channel mentions: mention @Light in any channel it's been added to, and it replies in a thread.

Privacy and security

Your expense submissions in Slack stay private. The bot works with you one-to-one in direct messages, and your expenses are visible only to you and your reviewers.

Also searched as: Slack expense bot, submit expense in Slack, send receipt to Light bot, Light Slack integration, expense reimbursement via Slack, upload receipt Slack, connect Slack to Light, Slack receipt upload, @Light bot, reimbursement status Slack.

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