ACM / Client / request_certificate



Requests an ACM certificate for use with other Amazon Web Services services. To request an ACM certificate, you must specify a fully qualified domain name (FQDN) in the DomainName parameter. You can also specify additional FQDNs in the SubjectAlternativeNames parameter.

If you are requesting a private certificate, domain validation is not required. If you are requesting a public certificate, each domain name that you specify must be validated to verify that you own or control the domain. You can use DNS validation or email validation. We recommend that you use DNS validation. ACM issues public certificates after receiving approval from the domain owner.


ACM behavior differs from the RFC 6125 specification of the certificate validation process. ACM first checks for a Subject Alternative Name, and, if it finds one, ignores the common name (CN).

After successful completion of the RequestCertificate action, there is a delay of several seconds before you can retrieve information about the new certificate.

See also: AWS API Documentation

Request Syntax

response = client.request_certificate(
            'DomainName': 'string',
            'ValidationDomain': 'string'
        'CertificateTransparencyLoggingPreference': 'ENABLED'|'DISABLED'
            'Key': 'string',
            'Value': 'string'
  • DomainName (string) –


    Fully qualified domain name (FQDN), such as, that you want to secure with an ACM certificate. Use an asterisk (*) to create a wildcard certificate that protects several sites in the same domain. For example, * protects,, and

    In compliance with RFC 5280, the length of the domain name (technically, the Common Name) that you provide cannot exceed 64 octets (characters), including periods. To add a longer domain name, specify it in the Subject Alternative Name field, which supports names up to 253 octets in length.

  • ValidationMethod (string) – The method you want to use if you are requesting a public certificate to validate that you own or control domain. You can validate with DNS or validate with email. We recommend that you use DNS validation.

  • SubjectAlternativeNames (list) –

    Additional FQDNs to be included in the Subject Alternative Name extension of the ACM certificate. For example, add the name to a certificate for which the DomainName field is if users can reach your site by using either name. The maximum number of domain names that you can add to an ACM certificate is 100. However, the initial quota is 10 domain names. If you need more than 10 names, you must request a quota increase. For more information, see Quotas.

    The maximum length of a SAN DNS name is 253 octets. The name is made up of multiple labels separated by periods. No label can be longer than 63 octets. Consider the following examples:

    • (63 octets).(63 octets).(63 octets).(61 octets) is legal because the total length is 253 octets (63+1+63+1+63+1+61) and no label exceeds 63 octets.

    • (64 octets).(63 octets).(63 octets).(61 octets) is not legal because the total length exceeds 253 octets (64+1+63+1+63+1+61) and the first label exceeds 63 octets.

    • (63 octets).(63 octets).(63 octets).(62 octets) is not legal because the total length of the DNS name (63+1+63+1+63+1+62) exceeds 253 octets.

    • (string) –

  • IdempotencyToken (string) – Customer chosen string that can be used to distinguish between calls to RequestCertificate. Idempotency tokens time out after one hour. Therefore, if you call RequestCertificate multiple times with the same idempotency token within one hour, ACM recognizes that you are requesting only one certificate and will issue only one. If you change the idempotency token for each call, ACM recognizes that you are requesting multiple certificates.

  • DomainValidationOptions (list) –

    The domain name that you want ACM to use to send you emails so that you can validate domain ownership.

    • (dict) –

      Contains information about the domain names that you want ACM to use to send you emails that enable you to validate domain ownership.

      • DomainName (string) – [REQUIRED]

        A fully qualified domain name (FQDN) in the certificate request.

      • ValidationDomain (string) – [REQUIRED]

        The domain name that you want ACM to use to send you validation emails. This domain name is the suffix of the email addresses that you want ACM to use. This must be the same as the DomainName value or a superdomain of the DomainName value. For example, if you request a certificate for, you can specify for this value. In that case, ACM sends domain validation emails to the following five addresses:

  • Options (dict) –

    Currently, you can use this parameter to specify whether to add the certificate to a certificate transparency log. Certificate transparency makes it possible to detect SSL/TLS certificates that have been mistakenly or maliciously issued. Certificates that have not been logged typically produce an error message in a browser. For more information, see Opting Out of Certificate Transparency Logging.

    • CertificateTransparencyLoggingPreference (string) –

      You can opt out of certificate transparency logging by specifying the DISABLED option. Opt in by specifying ENABLED.

  • CertificateAuthorityArn (string) –

    The Amazon Resource Name (ARN) of the private certificate authority (CA) that will be used to issue the certificate. If you do not provide an ARN and you are trying to request a private certificate, ACM will attempt to issue a public certificate. For more information about private CAs, see the Amazon Web Services Private Certificate Authority user guide. The ARN must have the following form:


  • Tags (list) –

    One or more resource tags to associate with the certificate.

    • (dict) –

      A key-value pair that identifies or specifies metadata about an ACM resource.

      • Key (string) – [REQUIRED]

        The key of the tag.

      • Value (string) –

        The value of the tag.

  • KeyAlgorithm (string) –

    Specifies the algorithm of the public and private key pair that your certificate uses to encrypt data. RSA is the default key algorithm for ACM certificates. Elliptic Curve Digital Signature Algorithm (ECDSA) keys are smaller, offering security comparable to RSA keys but with greater computing efficiency. However, ECDSA is not supported by all network clients. Some Amazon Web Services services may require RSA keys, or only support ECDSA keys of a particular size, while others allow the use of either RSA and ECDSA keys to ensure that compatibility is not broken. Check the requirements for the Amazon Web Services service where you plan to deploy your certificate. For more information about selecting an algorithm, see Key algorithms.


    Algorithms supported for an ACM certificate request include:

    • RSA_2048

    • EC_prime256v1

    • EC_secp384r1

    Other listed algorithms are for imported certificates only.


    When you request a private PKI certificate signed by a CA from Amazon Web Services Private CA, the specified signing algorithm family (RSA or ECDSA) must match the algorithm family of the CA’s secret key.

    Default: RSA_2048

Return type:



Response Syntax

    'CertificateArn': 'string'

Response Structure

  • (dict) –

    • CertificateArn (string) –

      String that contains the ARN of the issued certificate. This must be of the form:



  • ACM.Client.exceptions.LimitExceededException

  • ACM.Client.exceptions.InvalidDomainValidationOptionsException

  • ACM.Client.exceptions.InvalidArnException

  • ACM.Client.exceptions.InvalidTagException

  • ACM.Client.exceptions.TooManyTagsException

  • ACM.Client.exceptions.TagPolicyException

  • ACM.Client.exceptions.InvalidParameterException