Both apps let a tradesman send an invoice from his phone, capture a customer signature, and push the result into QuickBooks. That’s where the similarities end. Invoice ASAP has been around since 2010 and is built primarily for the solo end of field service. Billet is newer, launched in 2026, and is built for shops that send drivers out with trucks of inventory. Here’s the actual difference, by the numbers, with no marketing fluff.
Disclosure: this comparison is published by Billet and includes our own product. We’ve worked to keep it accurate and fair, but we are not a neutral third party.
Pricing
| App | Cheapest paid tier | What’s free | Top paid tier |
|---|---|---|---|
| Invoice ASAP | $3.99/user/mo Base | 30-day free trial | $14.99/user/mo Biz |
| Billet | $5/user/mo Essentials | 14-day trial, no credit card | $40/user/mo Professional |
Both apps bill per user. At the cheapest paid tier, Invoice ASAP’s Base is $3.99/user and Billet’s Essentials is $5/user. The bigger difference is at the accounting-sync tier: Invoice ASAP’s Biz plan (which adds QuickBooks Online sync) runs $14.99/user, while Billet includes all four accounting integrations (QuickBooks Online, Xero, FreshBooks, Microsoft Dynamics 365) on its $5 Essentials tier. On Billet, view-only office staff are free and don’t count toward the bill.
What’s in the box
| Feature | Invoice ASAP | Billet |
|---|---|---|
| Mobile signature capture | Yes | Yes |
| Per-signature GPS proof | Used for routing; per-invoice not documented | Yes, stamped on every signed PDF |
| Photo capture per invoice | Yes, unlimited | 5 / 10 / unlimited by tier |
| Offline mode | Yes (per vendor) | Built for offline; signing and sync queue work with zero signal |
| Tap-to-pay credit card | 2.9% + $0.30 | Stripe Connect at Stripe’s standard rate, 0% Billet fee on top |
| QuickBooks Online | Two-way | Two-way |
| Xero | Direction not publicly documented | Two-way, with Quote import and tax-rate sync |
| FreshBooks | Not advertised | Two-way |
| Microsoft Dynamics 365 | Not advertised | Two-way |
| Zapier app | Not listed | 6 triggers, 3 actions, 2 searches (coming soon) |
| Route optimization | Not advertised | Standard tier, Google Routes API |
| Fleet GPS map | Not advertised | Standard tier, live driver positions |
| Counter / kiosk mode | Not advertised | Yes, $5 per device |
Pricing and feature details are summarized as of June 2026 and change frequently. Verify current pricing and capabilities on each vendor’s own website before deciding.
Where Invoice ASAP wins
Lower entry price and a longer trial
If you’re a solo operator sending a handful of invoices a month, Invoice ASAP’s Base tier starts at $3.99/user, below Billet’s $5 Essentials, and it offers a 30-day free trial versus Billet’s 14 days. Invoice ASAP also includes unlimited photos on every tier. For a one-person side business those differences are real.
Mature in solo field service
Around fifteen years of plumbers and HVAC techs have shaped Invoice ASAP into something that fits the single-truck workflow naturally. The form fields, the recurring invoice setup, the deposit handling. It’s polished for that audience. Billet’s UX is built around someone leaving a warehouse with three deliveries in the truck, not someone diagnosing a leaky faucet.
Where Billet wins
GPS proof on every signature
This is the biggest single difference. Billet captures the device’s GPS location around the moment a customer signs, embeds it on the signed PDF, and stores it with the ticket in Billet. If a customer disputes the delivery, you have the timestamp, the GPS coordinates, and the customer’s signature on one document. Invoice ASAP uses GPS for travel-time reporting and route tracking, but per-invoice signature GPS is not a documented feature in the product.
For shops where a $4,000 boiler arrived at 8 in the morning and the customer is now telling their accountant nothing came, that single coordinate stamp is strong proof to help resolve the dispute.
Offline mode that actually works
Billet was built around the assumption that signal is going to drop. Warehouses with no cell service, customer driveways behind metal buildings, basements with one bar of LTE. Signing, photo capture, and the full sync queue all work fully offline. The queue processes the moment the device reconnects.
FreshBooks and Microsoft Dynamics integration
Invoice ASAP integrates with QuickBooks and Xero. Billet adds FreshBooks and Microsoft Dynamics 365 Business Central, both two-way. If you’re a Dynamics shop or a FreshBooks shop, Invoice ASAP isn’t on the table at all.
Counter Mode
A lot of distribution shops have a counter where walk-in customers pick up parts. Invoice ASAP doesn’t handle that workflow. Billet has a dedicated counter device mode: a tablet sits on the counter, the office assigns a ticket, the customer signs and optionally taps a card, done. Flat $5 per device per month on every tier.
Per-active-user pricing scales fairly for teams
Billet’s per-active-user $5 makes sense for teams that want every driver, every office user, and every counter station on the same shared dispatch view. View-only office staff are free and don’t count toward the bill, which keeps the price down as the office grows.
Which to pick
Pick Invoice ASAP if
- You’re a solo operator who needs an invoicing app on your phone
- You send fewer than 50 invoices a month
- You want the lowest possible entry price
- Your accounting software is QuickBooks or Xero only
- You don’t need GPS proof, route optimization, fleet visibility, or a counter
Pick Billet if
- You have a team (drivers, office staff, counter clerks)
- You deliver inventory rather than only service hours
- You want GPS embedded in every signature for proof of delivery
- You use FreshBooks or Microsoft Dynamics 365
- You expect to outgrow Invoice ASAP’s feature set within a year and don’t want to migrate later
The honest summary
Both are honest tools for honest work. Invoice ASAP is built for the one-truck plumber. Billet is built for the four-truck supply yard. Pick the one whose shape matches your shop, not the one that has the louder marketing.
If you’ve already got Invoice ASAP and the only thing you wish it had is signature-time GPS proof or proper offline mode or a counter device, Billet’s 14-day trial is the cheapest way to test whether the swap is worth it.
Try Billet free for 14 days
No credit card required. Connect QuickBooks, Xero, FreshBooks, or Microsoft Dynamics 365 during signup. Your first GPS-stamped signed invoice can go out this afternoon.