You've filled out the domain registration form, payment has been made, and then two days later an email arrives saying "the submitted documents are not approved." If you're looking for the exact amount and official definition, this is what you need to read before paying. Domain registration requirements vary so much between extensions that there's no single rule; some extensions only require a national ID card, some require residency in the relevant country, and some require nothing but an active email.
Extensions That Require Identity or Business Documentation
Country-code extensions (ccTLDs) almost always have an authentication layer on top of registration. The table below summarizes what you'll encounter in practice:
| Extension | Required Document | Residency Restriction | Minimum Length |
|---|---|---|---|
| .ir | IRNIC identifier (national ID or legal entity ID) | Yes, for Iranian natural persons | 3 characters |
| .de | Valid postal address in Germany | Yes | 1 character (with conditions) |
| .fr | Proof of presence in France | Yes | 2 characters |
| .ca | Presence Requirements (Canadian citizenship or company) | Yes | 2 characters |
| .us | Nexus Requirement (citizenship, residency, or business in the US) | Yes | 2 characters |
| .eu | EU citizenship or residency | Yes | 2 characters |
| .com / .net / .org | None | No | 2 characters (3 for new .com) |
| .io / .ai / .dev | None | No | 2 characters |
Practical note: for .ir you must first obtain an IRNIC identifier and link it to the domain. If you don't have an identifier, registration won't go through and the money won't be refunded either. Details of this process are covered in the complete guide to registering and managing .ir domains with an IRNIC identifier.
Character Count Limits and Allowed Characters
The minimum length for most new extensions is 2 characters, but some registries have made 3 characters mandatory. The maximum length is always 63 characters per label, not for the entire domain. That means a.b.c.example.com is valid, but no label can exceed 63 characters.
Allowed characters: letters a-z, digits 0-9, and hyphens. A hyphen cannot be at the beginning or end of a label, and two consecutive hyphens in positions 3 and 4 (like xn--) are reserved. IDN domains with Persian or Arabic characters are converted to Punycode format, and their final length is calculated after conversion, not before. A short Persian domain may exceed 63 characters after Punycode conversion and be rejected.
Allowed Registration Period and Renewal
The registration period varies from 1 year to 10 years, but not all extensions accept 10 years. .com and .net accept up to 10 years. .ir is usually 1 to 5 years. Some new extensions are only 1 year for the first time and then renewed annually.
Here's where people make a mistake: the user thinks that because they registered for 5 years, they have 5 years of leeway. In reality, auto-renew must be enabled in the panel, otherwise on the expiration date the domain goes into Redemption status. In that state, the recovery cost is several times the normal renewal and there's a limited time window. If your domain matters, turn on auto-renew and keep a valid bank card on file. The exact steps are explained in the guide to domain renewal and rescuing from expiration status.
Why Domain Registration Gets Rejected: Real Errors
Registry error messages are usually vague. A few cases I've actually seen:
Registrant verification failed— You haven't opened the verification email. ICANN requires for generic extensions that you respond to the verification email within 15 days, otherwise the domain is suspended.Invalid registrant data— The address or phone number doesn't match the format the registry expects. For.de, the address must actually be in Germany and DENIC verifies it.Domain already registered— The domain is in Redemption or Pending Delete status. You can't register it until the grace period ends.Invalid IDN encoding— The Persian domain exceeds the allowed limit after Punycode conversion or contains an invalid character.
To check whether a domain is truly available or in an intermediate state, use the DNS record lookup tool. If the domain is available but an old NS record comes back, it means it's still cached and your registration may take effect with a delay.
Extensions Restricted to Business and Brand
Some extensions are only open to companies registered in a specific industry. .bank requires approval from a banking regulatory body. .pharmacy is only for licensed pharmacies. .edu is for accredited educational institutions. You can't get these with an ordinary registrar; you must apply through the relevant registry and the approval process takes weeks.
In contrast, extensions like .dev and .app have no restrictions but are on the HSTS preload list. That means your domain won't open without SSL. If you don't have an SSL certificate, the user sees a security error. Consider this before registering.
Choosing an Extension: A Decision, Not a List
If your main audience is inside Iran and you want to be seen in domestic search results, .ir is the logical choice, provided you have an IRNIC identifier and can maintain the documents. If your business is international or you might move the server abroad later, choose .com and save yourself the hassle of documents and residency.
There's also a third scenario that's less often considered: choose the extension based on the target market, not based on cheapness. A cheap .de that gets rejected every year for not having a German address will end up costing more than an expensive .com. The real cost is time and follow-up, not the registration price.
To register and manage a domain, you can use domain search and registration and after registering, connect the domain to your own server. If you're working on a VPS, the guide to connecting a domain to a VPS from A record to SSL shows the exact order of steps. For dynamic domains and variable subdomains, also see managing wildcard records and dynamic subdomains.
Frequently Asked Questions
What documents are needed to register a .ir domain?
For a natural person, a national ID and IRNIC identifier. For a legal entity, a legal entity identifier and company registration documents. Without an IRNIC identifier, .ir registration won't go through. If you have an identifier but its information doesn't match the registration form information, the registry rejects the request.
Can I register a .de domain without German residency?
No. DENIC requires a valid address in Germany for .de registration and verifies it. Some registrars offer proxy services, but in that case legal ownership of the domain isn't yours and in case of a dispute, your access can be revoked.
What is the maximum number of characters in a domain name?
Each label is a maximum of 63 characters and the entire domain (with dots) is a maximum of 253 characters. The minimum length depends on the extension and is between 1 and 3 characters. For IDN domains, the length is calculated after Punycode conversion, not before.
If my domain expires, how much time do I have?
After the expiration date, you usually have a grace period of a few days during which renewal at the normal price is possible. After that, the domain goes into Redemption and the recovery cost is several times higher. After Redemption ends, the domain becomes available and anyone can register it. If your domain is your business brand, leave auto-renew on and don't filter the reminder emails.