If your substance has already been registered or data is available within the substance information exchange forum (SIEF), you should use the available information to the extent possible to understand if the Annex III criteria apply.

Your registration also needs to be in line with the joint submission obligation. This means that you need to discuss with other companies about substance sameness, share data and costs with them and, subsequently, submit your registration as part of a joint submission. Any relevant data you own must also be included in the registration dossier. 

Check ECHA's Annex III inventory of substances to see if your substance, any of its constituents, impurities or additives are listed there. If yes, go to step 3. If no, go to step 4.

If the information in the inventory shows that your substance has potential for carcinogenic, mutagenic or reprotoxic (CMR) (category 1A or 1B) or persistent, bioaccumulative and toxic (PBT) or very persistent, very bioaccumulative (vPvB) properties, you need full Annex VII information for your REACH registration except if you have valid reasons to disregard the information in the inventory.

If the information in the inventory shows that your substance is likely to be classified as hazardous to human health or the environment and it has diffuse or dispersive uses, particularly in consumer mixtures or in consumer articles, you also need full Annex VII information for your registration.

When assessing the uses, take into account in-house marketing information and information provided by customers or downstream sector organisations for characterising the uses of the substance.

However, you may have valid reasons to disregard the information in the inventory. If this is your case, you have to gather evidence from different sources and to show that you can still benefit from the reduced information requirements. The information sources you must check are listed under step 4.

You should also check the following information to see if your substance meets the Annex III criteria:

1. REACH registrations and notifications in the C&L inventory;
2. Other regulatory data available for the substance (e.g. Annex VI to CLP);
3. Available experimental data (e.g. in the QSAR Toolbox);
4. Alternatives to test data (e.g. QSAR, read-across, in vitro).

Based on the information gathered, one of the following cases will apply:

1. You already know that your substance fulfils at least one of the Annex III criteria. In this case, you must submit the full Annex VII with data with physicochemical, toxicological and ecotoxicological information in your registration.
2. You have concluded that your substance does not fulfil the Annex III criteria, but you have found your substance, or its constituent, impurity or additive in ECHA's Annex III inventory. You may have also found information from other sources that your substance is likely to meet the Annex III criteria.
   
   If so, you must provide a justification for disregarding this information in your IUCLID dossier to submit your registration with reduced information requirements.
3. You have concluded that your substance does not fulfil the Annex III criteria, and you have not found your substance, or its constituent, impurity or additive in ECHA's inventory. You have also not found any other indications from other sources that your substance is likely to meet the Annex III criteria. In this case, you can choose between two options:
   1. You can submit your registration dossier with physicochemical information only (and other relevant information available to you), with the relevant justification included in your IUCLID dossie
   2. You can submit your registration with full Annex VII information and claim a fee waiver to have a reduction in your registration fee. No justification is needed in this case.