# Quotas and Limits

EMQX Cloud sets default quotas (or limits) for each deployment and the default value of some of the quotas can be adjusted. The following tables show the default value of the quotas in different deployments and whether they can be adjusted. If you need to adjust the quotas, please contact us.

# Serverless

QuotasDefault ValueAdjustable
Maximum internal authentication entries2000NO
Maximum internal ACL entries2000NO
Maximum message queue length1000NO
Session expiry time(MQTT 3.x)2 hoursNO
Maximum retained messages2000NO
Maximum size of a retained message1mbNO
Retained message expiry intervalNeverNO
Client ID maximum length(MQTT 3.x)23NO
Client ID maximum length(MQTT 5.0)256NO
Maximum subscriptions for a single client10NO
TCP connect timeout10sNO
Number of deployments1YES
Number of subaccounts20NO

# Dedicated and BYOC

QuotasDefault ValueAdjustableRequires Deployment Restart
Maximum internal authentication entriesSession specification * 2NO-
Maximum internal ACL entriesSession specification * 2NO-
Maximum message queue length1000YESNO
Session expiry time(MQTT 3.x)2 hoursNONO
Maximum retained messagesSession specification * 10YESNO
Maximum size of a retained message1mbYESNO
Retained message expiry intervalNeverYESNO
Client ID maximum length(MQTT 3.x)23YESYES
Client ID maximum length(MQTT 5.0)256YESYES
TCP connect timeout10sYESYES
Number of deployments3YESNO
Number of subaccounts20NO-
What’s on this page