The move is an attempt to reduce problem gambling, as well as aiding general money management, allowing customers to switch off spending on betting sites via banking apps.
Gambling websites currently offer "time out" periods or self-exclusion but this does not stop players from being contacted by rival betting operators.
In December, Barclays became the first bank to introduce the option for customers to block debit card spending in other categories as well as gambling on its mobile app.
These categories include: groceries and supermarkets, restaurants, takeaways, pubs and bars, petrol stations, TV voting and pornography.
A Santander spokesman is quoted as saying by the Daily Mail: "We are working on functionality for debit card holders to turn off a number of broad categories of spend; for example, gambling."
A spokesman for RBS-owned NatWest is also quoted as saying: "We recently launched the ability for our customers to freeze their credit cards and set spending budgets using our mobile app and we are always looking at further ways to help customers manage their money."
