Munir Hassan Mohammed, 36, and Rowaida El-Hassan, 32, denied at the Old Bailey of planning to make a bomb or poison to use against British citizens.
Mr Mohammed denied a total of three terrorism offences, while Ms El-Hassan pleaded not guilty to two charges.
The pair, who were arrested during anti-terrorism raids, were remanded in custody and await trial in June.
Mr Mohammed, an Eritrean national seeking asylum in the UK, and Ms El-Hassan were arrested on 12 December.
They are jointly charged with preparing an act of terrorism between 7 July 2016 and their arrest last year.
The pair both pleaded not guilty to researching, planning and obtaining materials to produce an "improvised explosive device or poison" with a view to committing an attack in the UK.
Mr Mohammed, of Leopold Street, Derby, is further charged with being a member of Islamic State (IS).
He faces one other charge relating to the possession of information useful to terrorism and dissemination of terrorist publications.
Ms El-Hassan, of Willesden Lane, London, is further charged with possessing instructions on how to build an explosive device inside a mobile phone.
The pair were among six people arrested across the country, the rest of whom were released without charge.
A man and woman have pleaded not guilty to making preparations for a terrorism attack in the UK.