Too Many Queueable Jobs Added to the Queue: 51

What does this error mean?

Salesforce limits System.enqueueJob() calls to 50 per transaction. If you enqueue a Queueable job for each record in a bulk operation and that operation processes 51+ records, this limit is reached. The error is thrown immediately and the transaction is rolled back.

Note that within a Queueable's own execute() method, you may only enqueue one child job — this is a separate constraint from the 50-per-transaction limit that governs synchronous code.

Common Causes

1. System.enqueueJob() called inside a loop

The same anti-pattern as with @future — enqueuing a job per record in a trigger loop causes this error the moment a bulk operation exceeds 50 records.

2. Multiple independent Queueable dispatches per transaction

Different automation paths (flow + trigger + process builder) each enqueuing separate jobs in the same transaction, totalling more than 50.

How to Fix It

Solution 1: Enqueue one job with a collection of IDs

Design your Queueable to accept and process a Set<Id> so a single enqueue handles all records.

// ❌ BAD — one enqueue per record
for (Account acc : Trigger.new) {{
    System.enqueueJob(new MyQueueable(acc.Id));
}}

// ✅ GOOD — one enqueue for all records
System.enqueueJob(new MyQueueable(Trigger.newMap.keySet()));

// Queueable accepts a Set
public class MyQueueable implements Queueable {{
    private Set<Id> ids;
    public MyQueueable(Set<Id> ids) {{ this.ids = ids; }}
    public void execute(QueueableContext ctx) {{
        // process all records in ids
    }}
}}

Solution 2: Use Batch Apex for very large volumes

If the set of records to process is very large, Batch Apex is a better fit than Queueable. A single Database.executeBatch() call processes any number of records in chunked executions with fresh governor limits per chunk.