Gmail to Expensify: The Complete Workflow Guide

1. The Gmail → Expensify problem: ongoing plus backfill

If you've landed here, you probably already know the destination: receipts@expensify.com. Forwarding a single receipt there is well documented in our main Expensify email receipts guide. What that guide doesn't cover — and what this one does — is the real-world operational problem of connecting Gmail (personal or Google Workspace) to Expensify at scale, on an ongoing basis, and retroactively across years of old mail.

There are two jobs to solve, not one:

Native Gmail features are built around job #1 and mostly fail at it. None of them solve job #2 at all. That asymmetry is what this guide exists to untangle.

2. How Expensify receives mail (quick recap)

A two-sentence refresher so the rest of this guide makes sense. Expensify ingests receipts through receipts@expensify.com, and it only accepts mail from senders whose address is registered as a primary or secondary login on an Expensify account. SmartScan reads either the PDF/JPG/PNG attachment or the inline HTML of a forwarded vendor email and turns it into an expense under the sender's account.

3. Method A — Manual forward

The baseline. Open the receipt in Gmail, hit Forward, type receipts@expensify.com, send. Done. SmartScan handles the rest and the expense appears in your Expensify account a few minutes later.

Pros: zero setup, no permissions to beg for from IT, works identically on personal Gmail and Google Workspace, and every forward is intentional so you never accidentally send Expensify something that isn't a receipt. Cons: it depends on you remembering to do it every single time, which is exactly the kind of thing humans forget. If you only get a handful of receipts a month and you already live in your inbox, Method A is genuinely fine. Most people need something more durable.

4. Method B — Gmail filters: the verification trap

The next thing everyone tries is a Gmail filter with Forward it to set to receipts@expensify.com. In theory this is perfect: narrow the filter to from:(billing@stripe.com OR receipts@uber.com), set the action to forward, and you're done. In practice, you will get stuck on the very first step.

This is not a bug, a misconfiguration, or a missing permission. It's how Gmail is designed: the verification handshake exists to prevent malicious filters from silently exfiltrating your mail, and there is no user-facing way to opt out. Every personal @gmail.com account hits this wall.

5. Method C — Google Workspace routing rules

If your Gmail account is actually a Google Workspace account (your email lives on your own domain, billed to Google), there is a second lever that bypasses the verification trap entirely: Gmail routing rules in the Admin Console. Routing rules run at the MTA level before mail reaches the user's mailbox, and they do not require the destination to be verified.

Pros: no per-user verification handshake, centralised policy management, propagates automatically to every user in the Workspace domain, can scope to a shared billing alias or an entire department. Cons: it requires admin access you may not have, changes take up to about 20 minutes to propagate, and the matching syntax is substring- and regex-based rather than semantic — so a routing rule for subject:invoice will happily forward the marketing email whose subject line is "Invoice your friends for a free month".

Crucially, like every Gmail-native method: routing rules only apply to new mail going forward. They do not retroactively forward the 2,000 invoices already in everyone's inbox. For that, keep reading.

6. Method D — Apps Script and Gmail API

Method D is the DIY developer option. You write a Google Apps Script that uses GmailApp.search() to find matching messages and MailApp.sendEmail() (or GmailMessage.forward()) to push them to receipts@expensify.com. A time-driven trigger runs the script every 5, 10, 15, 30, or 60 minutes. No verification handshake required — the script sends as you, from your own mailbox, so Expensify sees an authenticated login as the sender.

function forwardReceipts() {
  var query = 'label:unprocessed has:attachment ' +
              '(subject:invoice OR subject:receipt)';
  var threads = GmailApp.search(query, 0, 20);
  threads.forEach(function (thread) {
    thread.getMessages().forEach(function (msg) {
      msg.forward('receipts@expensify.com');
    });
    thread.removeLabel(GmailApp.getUserLabelByName('unprocessed'));
    thread.addLabel(GmailApp.getUserLabelByName('sent-to-expensify'));
  });
}

Pros: works on personal Gmail (unlike Method C), can handle both ongoing forwards and — with a widened query and a higher batch size — a bounded historical backfill, and costs nothing if you stay inside Google's free quotas. Cons: you are now a script maintainer. When Google deprecates a method, or a vendor changes its subject format, or you hit a quota, the script stops silently.

The Gmail API route (instead of Apps Script) gives you finer control and cleaner OAuth scopes (gmail.send, gmail.readonly), but the quota and maintenance picture is the same. Method D is a solid fit if you already write code for a living and genuinely enjoy owning one more tiny system. For everyone else, skip to Method E.

7. Method E — Inbox-aware tools (Expensent)

Method E is the practical answer for almost everyone who landed on this page. It's an inbox-aware tool that connects to Gmail via OAuth — not through a Gmail filter — so the verification trap from Method B simply doesn't apply, and the backfill problem that Methods A–D cannot solve becomes a single scan through your history. Expensent is the tool we build; the rest of this section is specific to it.

Pros: sidesteps the verification trap, works on personal Gmail and Workspace identically, handles backfill (the one thing none of Methods A–D can do well), one-click rule creation from a real example, no scripts to maintain. Cons: it's a third-party tool, it's paid, and it asks for a Gmail OAuth scope to read and send mail on your behalf — the usual trade-off for any OAuth-based inbox tool.

If you want to go deeper, the Expensify integration page walks through the feature set, and our sibling guide on never missing a receipt in Expensify covers the longer-term habit side of the problem.

8. Which method for which user

Side-by-side, across the five methods:

Personal Gmail vs. Google Workspace in one line: personal Gmail users have Methods A, D, and E available; Workspace users also get Method C, but only if they have admin access or a friendly admin to file a ticket with. Method B is a dead end for everyone.

9. Backfilling years of historical receipts

Backfill is the job Gmail itself refuses to do. Filters and routing rules only act on incoming mail; they will not go back and re-send messages you received last year. If you just signed up for Expensify and want the last 24–36 months of receipts to actually live there, here are the realistic options in order of effort.

has:attachment filename:pdf
(subject:(invoice OR receipt OR "order confirmation")
  OR from:(billing@ OR invoices@ OR receipts@))
newer_than:3y

Whichever method you pick, do the backfill first, then switch on ongoing forwarding second. If you reverse the order, the tool will forward an invoice while it's also being backfilled, and you'll end up chasing duplicates in Expensify. Related reading: SmartScan troubleshooting for when backfilled receipts come through with missing data, and Expensify for accountants if you're doing this on behalf of a client rather than yourself.

10. Troubleshooting Gmail-specific quirks

11. Frequently Asked Questions