- Your payment was not fully processed or did not go through.
- Your domain is past the renewable period and the registry has to be contacted for manual renewal.
- There is a hold on your domain by the registry.
- Your TLD (mostly Country Code TLDs) have special registration/renewal requirements.
- Check on whois.com to find out if the domain is available for registration/renewal, contradicts the registry naming rules or has been reserved by the registry
- Make sure the domain you want to register does not have extended attributes, it it has you need to specify during checkout.
- Keep in mind that some TLDs (mostly Country Code TLDs) have special registration/renewal requirements.