Gmail to Expensify: The Complete Workflow Guide

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:

Gmail filters focus on new messages and require a verified forwarding destination. Historical receipts need a separate catch-up path.

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 associates mail with senders whose address is registered as a primary login or verified contact method on an Expensify account. SmartScan then reads clear attached receipt content and turns it into an expense under the sender's account.

Method A: Manual forward

The baseline. Open the receipt in Gmail, hit Forward, type receipts@expensify.com, send. SmartScan handles the receipt after it lands in your Expensify account.

Pros: zero setup, no permissions to beg for from IT, works in both personal Gmail and Google Workspace, and each forward is intentional, reducing the chance that you send Expensify something that isn't a receipt. Cons: it depends on you remembering to do it each 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.

Method B: Gmail filters and destination verification

A common next attempt 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.

Method C: Google Workspace routing rules

If your Gmail account is actually a Google Workspace account, there is an admin-level mail-routing tool in the Admin Console. It matters enough to mention here, but it is not the clean native answer many people hope it is.

The attraction is obvious: no per-user verification handshake, centralised policy management, and routing rules that can scope to a shared billing alias or an entire department. The catch is just as important: sender attribution can vary by routing setup, while Expensify ties emailed receipts to linked sender addresses. That makes Workspace routing a mail admin tool to test carefully, not a clean documented Expensify workaround. It also requires admin access you may not have, 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 old invoices already in everyone's inbox. Treat Method C as an admin caveat, not the main recommendation.

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 can run the script on a schedule. No Gmail forwarding-address verification handshake is required — the script sends as you, from your own mailbox, so Expensify can match the sender when that address is linked to the account.

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 can throw an exception or stop before the batch is complete.

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.

Method E: Inbox-aware tools (Expensent)

Expensent connects to Gmail through OAuth, finds current and historical receipt emails, and routes selected messages to receipts@expensify.com. Confirmed sender-and-subject patterns can then handle new recurring receipts automatically without Gmail's forwarding-address verification flow.

This route avoids Gmail forwarding-address verification, works with personal Gmail and Workspace, recovers historical inbox documents, creates rules from real examples, and avoids script maintenance. Expensent is a paid tool and uses Gmail OAuth permissions to find and send the relevant messages.

If you want to go deeper, the Expensify integration page walks through the feature set, and our sibling guide on preventing missing receipts in Expensify covers the longer-term habit side of the problem.

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.

Troubleshooting Gmail-specific quirks

Frequently asked questions