Finance · Do this yourself

Build expense reports automatically from email receipts.

How it makes money: Charge sales reps and consultants $12/mo to turn emailed receipts into expense reports.

Agent setup: Intermediate · Connects several tools (Lovable, Supabase) with payments and simple data. How we rate this

Found on Reddit in r/SideProject, r/n8n (2 threads).

🔥 32 posts this week · 13 likes

Based on u/Living-Ad-1109 on Reddit (opens in new tab)

Where this came from (Reddit)

Sales reps and consultants hate expense reports and fall weeks behind on matching receipts.

The threads (in our words)

Reddit blocks automated reads, so we couldn’t record upvote or comment counts. The business below is our own design inspired by these threads.

Who it’s for

Sales reps, consultants and small business owners.

Adapt it to your industry

  • Start with one niche or customer type, then expand.
  • Ask your first 10 customers what they would pay before you build more.
  • Keep a human check on anything sent in a customer’s name.

Step by step

  1. Connect read-only email access with the user’s permission and look for receipts.
  2. Use AI to read merchant, date, amount and tax from each receipt.
  3. Match receipts to card transactions the user uploads or connects.
  4. Export a PDF and CSV report in common expense formats.
  5. Charge a monthly plan through Stripe.
  6. Review failed matches weekly to improve the parser.

Ready-to-copy prompt

Here is a receipt image text: [paste]. Return merchant, date, total, tax, currency and a likely expense category as JSON.

Start with AI

Opens the AI with this guide and the prompt filled in.

Open in ChatGPT (opens in new tab)Open in Claude (opens in new tab)Open in Grok (opens in new tab)
Time
1–3 hoursOur estimate

Your autonomous stack

Autonomy: Reminders and reports run on a schedule from connected accounts. Your part: Weekly: check exceptions the agent flags (about 30 minutes).

Every layer an agent-run business needs, in order. Prices are public list prices, checked Oct 16, 2026.

  1. Agent (the brain): Grok Bot (agent + scheduled routines) (opens in new tab) (Included with The X Subscription Premium $30/mo (Super $100/mo for more usage; Plus $8 does not include Grok Bot)). Grok Bot runs the business day to day: writes, answers, decides small things and reports to you. Claude Code or Codex are alternatives.
  2. Build and hosting: Lovable (opens in new tab) (Free tier · Pro $25/mo), Supabase database (opens in new tab) (Free tier · Pro from $25/mo). The product or service your customers use.
  3. Payments: Stripe payments (opens in new tab) (No monthly fee · 2.9% + 30¢ per card payment). Automatic checkout and receipts. Other options: PayPal Checkout (3.49% + 49¢) or Lemon Squeezy (5% + 50¢, handles sales tax).
  4. Customer acquisition: Buffer (scheduled X posts) (opens in new tab) (Free plan (3 channels, 10 queued posts each) · Essentials $5/mo per channel, billed yearly), beehiiv newsletter (opens in new tab) (Free up to 2,500 subscribers), Apollo (find business emails) (opens in new tab) (Free tier · Basic $65/mo). Agent-written SEO pages, scheduled X posts and a weekly newsletter, plus cold email to businesses that follow CAN-SPAM/GDPR (real sender, opt-out link, no bought consumer lists).
  5. Delivery: Grok Bot (agent + scheduled routines) (opens in new tab) (Included with The X Subscription Premium $30/mo (Super $100/mo for more usage; Plus $8 does not include Grok Bot)). A Grok Bot routine delivers the product or result as soon as someone pays.
  6. Support: Grok Bot (agent + scheduled routines) (opens in new tab) (Included with The X Subscription Premium $30/mo (Super $100/mo for more usage; Plus $8 does not include Grok Bot)). Grok Bot answers the support inbox; anything unclear is flagged for you.
  7. Monitoring and schedule: Grok Bot (agent + scheduled routines) (opens in new tab) (Included with The X Subscription Premium $30/mo (Super $100/mo for more usage; Plus $8 does not include Grok Bot)). Grok Bot scheduled routines run each day: send, check for failures, alert you if something breaks.
  8. Analytics: Google Analytics (opens in new tab) (Free). Tracks visits, signups and sales so the agent can report what works.
  9. Human checkpoint: Weekly: check exceptions the agent flags (about 30 minutes).
  10. Price: charge $12 per subscriber (monthly plan). Offer the first 3 customers a founding price for honest feedback.
Monthly cost$30–$150/monthFree tiers → paid plans of the tools above. Card fees come out of each sale.
What you could earn · EstimateEstimate: 120 subscribers × $12 = $1,440/moOur estimate, not a fact or a promise. It’s simple math if you land these customers at this price.
Details: source, numbers and tags

What they did

An agent finds receipts in the inbox, matches them to card charges and produces a ready-to-submit report. We designed this business from real Reddit threads; it is an idea for you to build, not a description of the posters’ businesses.

How it went

Found on Reddit in r/SideProject, r/n8n (2 threads). Upvote and comment counts weren’t retrievable, so none are shown. On X, 32 posts matched our search for this idea in the 7 days to 2026-10-16.

Worth knowing

Ask only for the access you need and say how data is stored. Google requires a security review for Gmail access.

Difficulty
BeginnerOur rating
Time to build
Not reportedOur estimate
Monthly cost
Not reported
Revenue
Not reportedWe only show revenue the source states
Engagement
No public countThe source shows no number
X buzz
19.7 · 32 posts in 7 days13 likes, 3 reposts, 3 replies, 0 quotes on 14 top posts · fetched Oct 16, 2026 · query: ("expense report" OR "expense reports") (hate OR receipts OR nightmare OR behind) -is:retweet lang:en

Posted · Added Oct 16, 2026

Original builder recipe

  • ChatGPT
  • Claude
  1. Connect read-only email access with the user’s permission and look for receipts.
  2. Use AI to read merchant, date, amount and tax from each receipt.
  3. Match receipts to card transactions the user uploads or connects.
  4. Export a PDF and CSV report in common expense formats.
  5. Charge a monthly plan through Stripe.
  6. Review failed matches weekly to improve the parser.

Tags

Read the original

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