Frequently Asked Questions

PromptFax is an online fax-sending service for people who need to send a fax without using a fax machine, fax line, subscription, or account.

You upload your document, review the pages, enter the recipient's fax number, get a quote, authorize payment, and PromptFax sends the fax.

Many online fax services use dark patterns and tricks to recoup their costs through automated monthly subscriptions.

PromptFax is designed for when you only want to send one fax. We make this as quick and easy as possible. We do not do accounts, trials, or subscriptions.

No surprise bills. No spam. No feature gating. No upsells. No dark patterns. No tricks. No games. No gimmicks. You only pay for what you fax, and that is it.

No. PromptFax is built for one-off faxing with no signup, no trial, and no account creation. There is no ability to create an account.

No. PromptFax is currently for sending outbound faxes only. It does not currently provide a fax number for receiving inbound faxes.

No. You need the recipient's fax number, but you do not need your own fax machine, fax line, or fax number to send through PromptFax.

PromptFax costs $2.00 for the first 5 pages, then $0.10 per additional page, capped at $4.50 for up to 35 pages.

For example, 4 pages costs $2.00, 6 pages costs $2.10, 10 pages costs $2.50, 25 pages costs $4.00, and 35 pages costs $4.50.

Upload your document to get an exact quote before paying or use the pricing calculator on the Pricing page for a quote.

When you are ready to send your fax, PromptFax opens a secure Stripe payment panel where you enter your payment information. Payment is processed by Stripe for Cogint Labs LLC, the operator of PromptFax. PromptFax accepts major credit and debit cards through Stripe.

PromptFax prepares the fax first, then asks you to authorize payment before sending. You will only be charged after there is an actual fax delivery.

PromptFax is operated by Cogint Labs LLC, so Stripe may show Cogint Labs LLC on payment screens, receipts, or card statements.

If your payment is charged, Stripe may email a receipt to the email address you enter in the secure payment panel. The receipt comes from Stripe for Cogint Labs LLC, the operator of PromptFax.

PromptFax authorizes payment before sending, but only captures payment after delivered pages are confirmed. If no pages are delivered and the authorization is released, there is no Stripe charge and no Stripe payment receipt.

The Stripe receipt is separate from the PromptFax delivery report. After delivery, PromptFax shows a browser-local delivery report with delivery details and preview images of the pages that were sent.

No. Uploading a file does not send the fax. PromptFax prepares the document, checks the pages, and gives you a quote first.

The fax is only sent after you authorize payment.

Yes. You can stop before authorizing payment. Once a fax transmission has started, cancellation may not be possible because the fax is already being transmitted through the phone network.

PromptFax currently accepts PDF, JPG, JPEG, and PNG files.

You can upload one file or combine multiple files into one fax, as long as the total document stays within the page and file-size limits.

Yes. You can add multiple files, up to 35 total pages and 50 MB total across all files.

PromptFax supports up to 35 pages per fax. For longer documents, split the document into multiple faxes.

You can use the page editor to remove or reorder pages before sending.

Yes. You can send the same assembled document to more than one destination while the session is still available. Each destination is a separate fax transmission and requires its own payment authorization.

Yes. PromptFax accepts image files produced by modern cameras. Supported image types include JPG, JPEG, and PNG.

For best results, use a clear document scan instead of a casual photo. Make sure the full page is visible, the text is readable, and the image is not blurry or shadowed. We recommend using your phone's document scan features if available.

Open https://promptfax.app on your phone and tap Add pages. You can take a photo with your camera or choose photos you already took.

For the cleanest scan, use your phone's document scanner first, then upload the PDF. On iPhone or iPad, use Notes or Files -> Scan Documents. On Android, use Google Drive, Files by Google, or your phone's built-in camera scan option.

Apple documents scanning through Notes and Files, while Google documents scanning through Drive and Files by Google; Pixel devices can also scan from the camera when the document prompt appears.

Not yet. Automatic cover-page creation is planned but is not currently part of the public flow.

You can create your own cover page using one of the templates below, save or export it as a PDF, and add it to your fax before the other pages.

• Google Docs template
• Microsoft Word template
• Apple Pages template

Not yet. Automatic image cleanup is planned but is not currently available.

For best results today, use your phone's document scanning feature before uploading images. A document scanner usually produces a cleaner fax than a normal camera photo.

PromptFax currently supports faxing to US numbers only.

Enter the destination fax number and PromptFax will confirm whether it is supported before you pay.

You need the recipient's fax number. A regular voice phone number will not receive a fax unless that line is connected to a fax machine or fax service.

If you are not sure whether the number accepts faxes, check with the recipient before sending.

PromptFax works best in current versions of modern browsers, including Chrome, Edge, and Safari.

For phone and tablet use, we recommend current Chrome on Android and current Chrome or Safari on iPhone or iPad. Older mobile browsers, embedded browsers, and unsupported operating-system versions may experience issues.

We recommend the following browsers:

• Chrome desktop and Android: version 118+
• Edge desktop and Android: version 118+
• Safari on macOS: version 16.4+
• Safari or Chrome on iPhone and iPad: iOS/iPadOS 16.4+

Fax transmission can take 30 to 90 seconds per page, plus setup time for the fax call. A short fax may complete in a couple of minutes, while a longer fax can take several minutes or more.

Transmission time depends on the number of pages, image complexity, fax resolution, phone-line quality, and the receiving fax machine or fax service. Plain text on a clean white background usually sends faster than photos, detailed scans, or pages with heavy graphics.

Yes. After PromptFax receives the final delivery result, it shows a delivery report in your browser with the destination, sending number, delivery time, delivered page count, charge amount, transmission ID when available, and preview images of the pages that were sent. You can view, open, or download the report as a PDF. The report is kept locally in your browser for up to 24 hours after last activity unless you clear your data sooner.

Fax is slow because it was designed to work over old-school phone lines, not the modern internet. Even when you upload a document instantly, the receiving fax machine still must use decades old technology for transmission.

Before the pages are sent, the sending and receiving fax systems need to connect, exchange tones, negotiate a speed, and confirm that pages were received. If the receiving line is busy, the connection is noisy, the fax machine is older, or the document has complex images, the transmission can slow down or require retries.

Most fax pages take about 30 to 90 seconds per page, plus connection setup time. Simple black-and-white text pages are usually faster than photos, scans, or pages with heavy graphics.

If the fax does not go through, PromptFax will show the failure status when it receives the result from the fax provider. Common causes include a busy line, no answer, an invalid fax number, poor line quality, or the receiving fax machine rejecting the transmission.

If the fax fails before any pages are delivered, you can try again. If some pages were delivered before the transmission stopped, you can use the page editor to send only the remaining pages.

PromptFax is designed to charge only for pages that PromptFax records as successfully delivered. If no pages are delivered, you are not charged for delivered pages.

For example, if you send a 13-page fax but the transmission disconnects after 11 pages, you would only be charged for 11 delivered pages: $2.00 for the first 5 pages plus $0.10 for each of the next 6 pages, for a total of $2.60.

PromptFax can confirm whether the fax provider reported pages as delivered, but it cannot control how the receiving fax machine prints, stores, routes, or displays the pages after delivery.

PromptFax keeps files only as long as needed to prepare, send, and report on the fax. Files may be processed locally in your browser and temporarily stored on PromptFax servers during the fax workflow.

Server-side working copies are deleted after the workflow is complete. Some session information may remain on your device until you clear it or the session expires.

PromptFax does not require an account or collect an email address to use the app.

Stripe, PromptFax's payment processor, may request payment-related information during checkout. The transaction takes place on Stripe's servers and PromptFax does not receive any user or card information from Stripe.

We take great care to keep your documents, which may contain Protected Health Information (PHI) private and protected. We only keep your documents only as long as needed in an encrypted form for transmission. We delete your document from our servers after successful transmission and any information retained is local to your device where you may clear it at any time. We do not collect email addresses.

We are not lawyers and this is not legal advice, but we believe services like PromptFax fall under the Conduit Exception. We do not currently offer a HIPAA Business Associate Agreement (BAA).