UPDATED 1pm:

Xero says the problem has been resolved.

EARLIER:

Xero [NZX: XRO] has been experiencing problems with its servers all morning, with numerous customers saying they can’t log in to the accounting software company’s cloud platform.

“We are currently experiencing an issue within our application hosting infrastructure that is affecting a proportion of Xero customers. Xero’s operations team is working to identify and resolve the cause of the issue as soon as possible,” the listed company says in a blog.

At midday, Xero said it had identified the issue and its provider is working to fix the affected hardware.

"The outage is now affecting all users. We cannot tell you how sorry we are about this interruption. We are working hard alongside our provider to get this resolved," Xero said in an update.

Status website isitdownrightnow.com suggests Xero is having problems worldwide.