Google is working on a project codenamed \"Pony Express\" that lets users pay their bills directly from Gmail Justin Sullivan/Getty Images

Google is currently working on a project that will enable Gmail users to be able to pay their bills directly from their email inbox – the logical next step after enabling users to attach and send money to each other.

The project, codenamed "Pony Express", was laid out in a lengthy document seen by tech news site Re/code and is expected to start in the fourth quarter of 2015.

The document details a step-by-step walkthrough of how users can sign up for the service. Designed to work in the US, users will have to provide personal details including their full name, address and partial and full Social Security number to a third-party company in charging of vetting their identity.

Users might also be required to link their full credit card number or telephone service account number to their Gmail account, and the idea is that third-party vendors would work with Google to email out bills on behalf of utility providers, or telecom and insurance companies.

Pony Express: Signing up process
A screenshot of the Pony Express sign-up process to authenticate the user as a bill payer Re/code and Google

Once authenticated, the user could login to Gmail or the Inbox app and pay for e-bills using a credit or debit card.

The bill would be organised in a special chronological folder, and there's even the option for a user to automatically split a bill with another Gmail user, which would be useful for housemates sharing utilities at the same residence.

Pony Express: Paying bills on the app
A screenshot showing the Pony Express interface where bills are listed and stored for easy reference Re/code and Google

The idea of making bills digital is not a new one, and many banks and service providers around the world are now going paperless.

The app Mint Bills (formerly Check, before it was bought by Intuit in 2014) monitors your credit card account and bank accounts, as well as reminding you when bills are due, and the app allows you to pay for bills directly from the app using linked payment sources and bank-level security.

Other apps that have tried to do the same thing have not been so successful, such as the now defunct Hearst-owned account management app Manilla.

Google's Pony Express could be successful in marrying online payments with e-bills as it has the benefit of having a huge audience that uses its services.

Plugging in the ability to pay instantly with the tap of a few buttons would be attractive to users, if they can get over their security concerns regarding Edward Snowden's NSA spying revelations and Google reading their mail to serve targeted advertising.