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SF-0043 · Scenario · Medium

A roll-up summary option is disabled in one of the objects. What is the reason?

✓ Verified by Vikas Singhal · Last reviewed 5/17/2026

When you go to Setup → Object Manager → [Object] → Fields & Relationships → New and the Roll-Up Summary option is greyed out (disabled), there is one fundamental reason: the object has no master-detail children. Roll-Up Summary fields aggregate data from child records, and they only work when the child is in a master-detail relationship with the object you’re trying to add the field on.

The root cause

Roll-Up Summary requires a master-detail relationship for two structural reasons:

  1. The aggregation must be transactionally consistent — every insert/update/delete on the child needs to recalculate the parent. Master-Detail’s strict cascade guarantees that the parent always knows about its children. Lookups don’t carry that guarantee (children can detach or be re-parented loosely).
  2. The recalc engine needs to know which children belong to which parent, with cascade integrity. Master-Detail provides that schema-level lock.

Without at least one master-detail relationship where the current object is the master (parent), there’s nothing to roll up from.

Common causes when the option is disabled

1. No master-detail relationship exists yet

The object has only Lookup relationships from its children. Solution: identify the candidate child, ensure all rows have a non-null parent lookup, then convert the child’s Lookup → Master-Detail.

2. The object is the child in a master-detail, not the parent

Roll-Up Summary lives on the master (parent) side. If you’re on the child object, you’ll only see Roll-Up Summary disabled — even though a master-detail exists, it’s pointed the wrong direction for what you’re trying to do.

Solution: go to the parent object and create the roll-up there.

3. Object is a standard object that doesn’t permit roll-ups

A small number of standard objects can’t host roll-ups for platform-internal reasons. The most common workaround is to keep the data in a custom related object and roll up there.

4. The object has reached the per-object roll-up summary limit

Each object can have a limited number of roll-up summary fields (commonly 25, but check the current Salesforce limits page). If you’ve hit the cap, “Roll-Up Summary” is disabled until you delete one.

5. Object type doesn’t support roll-ups at all

  • External Objects (__x) — no roll-ups
  • Big Objects (__b) — no roll-ups
  • Knowledge / Article-Type objects in some configurations — limited

If the object is one of these, Roll-Up Summary will be disabled regardless of relationships.

6. The object is a junction object

Junction objects (two master-detail children) can be aggregated but you wouldn’t typically create roll-up summaries on a junction. The disabled option here is usually because junctions don’t have their own master-detail children.

7. Permission / org setting

In rare cases, the option is hidden because the running user’s profile lacks the Customize Application permission. Less commonly, the org is in a Salesforce edition (e.g., Group, Essentials) where roll-up summaries are restricted.

Troubleshooting checklist

  1. Are you on the parent object? Roll-Up lives on the master side. Confirm you’re looking at Fields & Relationships of the parent, not the child.
  2. Does the parent have any master-detail children? Check Object Manager → Fields & Relationships of the child objects to see what’s a M-D vs Lookup. If everything’s Lookup, you need to convert one.
  3. Is the object type supported? External, Big, and certain configured objects are excluded.
  4. Have you hit the limit? Count existing roll-ups on the object.
  5. Do you have Customize Application permission?

How to fix the typical case

“I have Account and a custom Account_Visit__c with a Lookup to Account. Roll-up summary on Account is greyed out for visits.”

This is the classic case — Account.AccountId from Account_Visit__c is a Lookup, not a Master-Detail.

You cannot fix this directly because Opportunity.AccountId-style standard relationships are intentionally lookup (so the standard Account → Opportunity can’t be M-D). For a custom child object, you can:

  1. Backfill all Account_Visit__c.Account__c lookup values (no nulls).
  2. Convert the Account__c field from Lookup to Master-Detail.
  3. Now Roll-Up Summary is enabled on Account.

For standard relationships you can’t convert (Opportunity, Contact, Case to Account), use an alternative: Declarative Lookup Rollup Summaries (DLRS) AppExchange package, a flow with scheduled calculation, or a Apex trigger.

What if I just need an aggregate one time?

If you don’t need a live roll-up — just a one-shot aggregate for a report — use a Summary report grouped by parent, or a report formula. No master-detail required.

Summary

Roll-Up Summary is disabled when the object has no master-detail children to aggregate from. Convert a Lookup to Master-Detail (if possible), check you’re on the parent side, and verify the object type supports the feature.

Verified against: Salesforce Help — Roll-Up Summary Field Considerations. Last reviewed 2026-05-17.