NHS Choices and NHS Direct have both launched SMS text services to help patients find their nearest NHS service providers.
The two organisations, which are currently locked in talks with the Department of Health over which should carry what information, deny they are duplicating services.
NHS Direct began piloting its service in December. It involves people texting their postcode and the type of service for which they require information, for example GP services, dentistry or accident and emergency. They get information drawn from the NHS Choices website sent by SMS to their mobile phone.
The NHS Choices pilot, which has not had a high-profile launch but has been available through the website since the beginning of the year, also sends details of local A&E services or GP services to a user in response to the message 'A&E' or 'GP'.
However, it also works out where the sender is texting from and relays information relevant to their location and is delivered in conjunction with Directgov.
A spokesperson for NHS Direct said: "They are using very different technology and we don't think this is duplication."
An NHS Choices spokesperson said it had been working with NHS Direct to pilot an SMS "text-back" mobile service using the data provided by NHS Choices.
"We will use the experience of this pilot to produce an integrated online and digital health information service," the spokesperson said.