Most countries will accept corrected applications. VAT4U will advice you about how these should be submitted through the electronic facility in your own member state.
Please be aware that the tax authorities may impose penalties for applications which are found to be incorrect, so if you realise that you have made an error on an application after it has been submitted, you should submit a correction as soon as possible. You can use the correction procedure to amend existing claim lines, you can not delete a claim line but you can reduce the VAT value to zero, and you may not insert additional lines. If you have missed an invoice from an application, you should include it on a later one. You should also use the claims procedure to amend your e-mail address or bank details, if these change after you have submitted your application. Corrected applications must be submitted by the same deadline as original applications, that is, by 30 September of the year following the year in which the VAT was incurred.