There are a few reasons why you might consider doing this. It keeps things smooth when it comes to the claims process: if your partner is involved in an incident and needs to claim, a separate policy means your premium and no claims bonus won’t be affected – and vice versa.
In addition, if your partner is a higher risk driver – through age, inexperience or any previous convictions – they’re going to face higher premiums. If you have a joint policy, that would affect what you pay too. So if you want to keep your own premium down, consider separate policies.
Furthermore, you may want separate policies to reflect different needs of cover. Perhaps you want a fully comprehensive policy with all the trimmings like breakdown cover and no claims bonus protection, but your partner only wants third-party. Unless you have similar requirements when it comes to car insurance, you could be better off taking out individual policies.
On the other hand, having a joint policy does have its benefits. Combining your policies tends to save money overall on your collective premiums as you’re not paying certain things twice. Or, if your partner drives the vehicle less then you, then you could instead add them as a named driver to your own insurance. However, if you use the vehicle in equal measure then you’ll need to take out a joint policy to reflect that, else it’s considered fraud.