That means PayPal won't charge a premium if you can pay back the money you borrowed within four months. Anything left over after this period will, however, be subject to a typical interest rate of 17.9 percent p.a (variable). PayPal is basing that figure on an "assumed" credit limit of £1,200 -- both could vary depending on your particular circumstance. Furthermore, The four-month window isn't a one-time promotion, so you'll be eligible for the scheme every time you order something that's worth more than £150.

The only caveat is that the place you're buying from has to support PayPal. That could be a website or a brick-and-mortar store, however.

In addition, PayPal has partnered with the following retailers to offer alternative instalment plans: Blacks, Chain Reaction Cycles, Dyson, Millets, Samsung, Simply Games and Ultimate Outdoors. Dyson, for instance, will give 14.9 percent interest over a six, 12 or 24 month period on orders over £199. Chain Reaction Cycles, meanwhile, is offering zero percent interest for purchases as low as £99, with either a 12 or 24 month plan.

Many companies, especially those making or selling luxury goods, already offer their own instalment plans. To be successful, PayPal will need to stay competitive with its own deals and interest rates, and continue to thrash out similar deals that can be picked up through its retailer partners. Amazon, for instance, has a similar scheme in the UK called Pay Monthly, however it's only eligible for orders made through its own storefront.

PayPal Credit was available before, but in a limited capacity. It launched in the UK back in 2014, starting with what the company has described as a "successful pilot." PayPal's ambitions have grown since then though, teaming up with companies like Apple to offer zero-interest monthly payment plans. Starting today, the service is available nationwide, and with more retailers offering PayPal-exclusive instalment options. It signals a large, important push on PayPal's part to attract new users and make PayPal Credit a service that's widely recognised by the British public.