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Domain control validation backoff schedule

Domain control validation (DCV) has to happen before a Certificate Authority (CA) will issue a certificate for a domain. If DCV fails, Cloudflare automatically retries it on a schedule.

DCV happens with Cloudflare’s CA partners according to the following schedule:

  • DigiCert - 30 days
  • Google Trust Services - 14 days
  • Let’s Encrypt - 7 days

Afterward, DCV tokens expire as dictated by the CA/B Baseline Requirements, which govern issuance of publicly trusted SSL certificates.

Here is the function that is used to determine the next check:

now() + min((floor(60 * pow(1.05, retry_attempt)) * INTERVAL '1 second'), INTERVAL '4 hours')

As the table below shows, most of the checks take place on the first day. Most validations complete within the first five minutes, unless the customer has misconfigured the CNAME to your domain. We cap the check backoff to a maximum of four hours to avoid the function growing exponentially, which would result in large gaps between checks towards the end of the month.

Retry AttemptIn SecondsIn MinutesIn Hours
0601.0000.016667
1631.0500.017500
2661.1000.018333
3691.1500.019167
4721.2000.020000
5761.2670.021111
6801.3330.022222
7841.4000.023333
8881.4670.024444
9931.5500.025833
102424.0330.067222
112794.6500.077500
123215.3500.089167
133696.1500.102500
144247.0670.117778
154888.1330.135556
165619.3500.155833
1764510.7500.179167
1874212.3670.206111
1985314.2170.236944
2098116.3500.272500
21112918.8170.313611
22129821.6330.360556
23149324.8830.414722
24171728.6170.476944
25197532.9170.548611
26227137.8500.630833
27261243.5330.725556
28300350.0500.834167
29345457.5670.959444
30397266.2001.103333
31456876.1331.268889
32525387.5501.459167
336041100.6831.678056
346948115.8001.930000
357990133.1672.219444
369189153.1502.552500
3710567176.1172.935278
3812152202.5333.375556
3913975232.9173.881944
4014400240.0004.000000
4114400240.0004.000000
4214400240.0004.000000
4314400240.0004.000000
4414400240.0004.000000
4514400240.0004.000000
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4814400240.0004.000000
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5014400240.0004.000000
5114400240.0004.000000
5214400240.0004.000000
5314400240.0004.000000
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5514400240.0004.000000
5614400240.0004.000000
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