When a backer’s payment can’t be collected, we’ll email them with instructions on how to fix their pledge and will continue to do so every 48 hours for 7 days. They can also fix their pledge by logging into their Kickstarter account and clicking on the "Fix Payment" banner at the top of the page.
Backers with errored pledges will have 7 days from the project's deadline to update their payment method. At the end of this period, we’ll automatically try to collect their pledge again. If this attempt fails, these backers will be dropped from the campaign and it will no longer be possible to collect their pledge.
You're welcome to reach out to these folks and try to arrange an alternative method for them to support your project. Please note, however, that any additional contributions beyond the project deadline will not be reflected on Kickstarter – both on the backer’s account or in your Backer Report.