https://www.epo.org/en/node/what-happens-after-i-upload-one-or

What happens after I upload one or more documents using the Contingency Upload Service?

The documents that you upload using the Contingency Upload Service are stored encrypted, and the timestamp of the upload is logged.

Upon the successful upload, you will receive an automated email acknowledging the receipt of the documents, along with the timestamp of the receipt and a unique reference code for your upload. 2

The Contingency Upload Service does not perform the business validations normally performed by the EPO filing tools. Therefore, subsequent processing will be required by the EPO after your documents have been uploaded, for them to be incorporated into the file held by the EPO and be treated as part of the Patent Granting Process.

According to the above, if your upload concerns a new European patent application or international application, the email acknowledging the receipt of your documents will not contain an EP application number or PCT application number. This will be issued by the EPO upon the successful processing of your upload.