AIG Life is the new sole provider of protection products for Royal Bank of Scotland, NatWest and Ulster NI banking customers.
RBS and AIG have been working together to design a simple protection proposition for bank customers.
Most customers will be asked just 11 questions with the majority being offered instant cover without the need for medical evidence.
The products available from this week's launch will be Life Insurance; Critical 3 with Life; and a guaranteed acceptance whole of life insurance product called Guaranteed Sixty Plus.
This includes a protected insurance feature so customers who have paid half the premiums due before their 90th birthday receive a partial payout even if they stop paying premiums.
Royal Bank of Scotland, NatWest and Ulster NI customers will be able to buy cover online, in branch or over the telephone.
There is also an easy-to-use online life insurance calculator to help customers work out how much cover they need and of what type, plus live support via phone or web chat.
RBS head of insurance & protection products Sam Kerr said: "We have been very impressed by AIG Life's ability to deliver a proposition that meets our customers' needs. We want to lead the way with clear, good value products and a simple application process.
"This new partnership means that we can offer our customers the right products, in the right way, at the right time."
AIG Life CEO Adam Winslow added: "We are delighted RBS chose us to protect Royal Bank of Scotland, NatWest and Ulster NI customers.
"This is our biggest partnership to date and I am very proud of the proposition that we have developed together for launch.
"I'm also looking forward to working together with RBS to continue to innovate for the benefit of customers as our partnership grows."
A 'sensible' Budget
Hiding in plain sight
Chancellor Philip Hammond addressed MPs on 22 November
Active management at passive costs
Introduction to group risk – Part 6