Late-night online access to credit is leading people to borrow more money than they can afford to repay, according to academics.
Newcastle University researchers said a ban on online borrowing - primarily through payday loans - between 11pm and 7am could protect consumers.
Money is often borrowed to fund late-night, impulse buying, they said.
The option for people to block spending on gambling sites is already available on various apps.
The research, funded by the Economic and Social Research Council (ESRC), warned that people were being encouraged to borrow more than they could pay back because sites were designed to give a false sense of control. It also found that people's mental health could be affected.
"Urgent reforms are needed to protect consumers from financial and psychological risks," said lead researcher Dr James Ash.
"The shift online has increased availability of payday loans to people previously excluded by mainstream lenders.
"But our research shows that digital access to credit only offers quick fixes - it does not address borrowing's root cause."
Researchers interviewed borrowers, analysed websites, and spoke to debt charities.
They found that some borrowers welcomed not having to explain themselves or face being judged, or rejected, by a real person when applying for loans online.
However, the result was that they were targeted by loan providers with messages about extra credit through mobile devices.
The Consumer Finance Association, which represents a number of short-term lenders, said: "The modern economy, and changing nature of the UK workforce, mean that financial needs are no longer restricted to regular business hours.
"The [researchers] clearly want to ignore the benefits of these loans, but for hundreds of thousands of customers this is an important financial service and something that they can now access when convenient for them."