ECHA just published its latest tip of the week on how to create a joint submission for your substance. If you are going to register a substance as the lead registrant by the 31 May deadline, create a joint submission for it in REACH-IT by 9 May at the latest. If no joint submission has been created, ECHA will assume that the substance will not be registered.

You can find more information, on what to do when you want to register a substance, on the <link https: echa.europa.eu support registration working-together practical-advice-for-new-siefs _blank>ECHA website.