Data Hygiene5 min read

Custom Fields in CRM: What to Add and What to Skip

Q: How many custom fields should a CRM have?

There's no magic number, but a good rule of thumb is 5-15 per object (contacts, deals). More than 20 and you're likely creating clutter. Audit quarterly and remove fields with < 30% fill rate.

Q: Should I use tags or custom fields?

Use custom fields for structured data you want to filter and report on (Industry, Lead Source, Contract Date). Use tags for ad-hoc, flexible grouping (event attendance, campaign membership). Tags are easier to add; custom fields are more powerful for analysis.

Q: What's the best field type for custom data?

Dropdowns for anything with known options (Industry, Lead Source, Deal Type). Numbers for quantitative data (Employee Count, Revenue). Dates for time-based triggers (Contract End, Last Contacted). Free text only for truly unstructured data.

Q: How do I get reps to fill in custom fields?

Three strategies: make them required at stage transitions, auto-populate through enrichment/API, and show reps how the data helps them (e.g., better pipeline views when Industry is filled). Mandatory + automated = high adoption.

Custom fields are the most powerful — and most abused — CRM feature. Add the right ones and you unlock reporting and automation. Add the wrong ones and you end up with 47 fields nobody fills in.

Key Takeaways

Only add custom fields you will actually filter, report on, or automate against.
Use typed fields (dropdown, number, date) — not free text — for anything you want to analyze.
Tags are for ad-hoc grouping. Custom fields are for structured, reportable data.
Audit fields quarterly — if nobody has filled a field in 90 days, delete or archive it.

Good Custom Fields vs. Bad Ones

Field	Type	Verdict	Why
Lead Source	Dropdown	✅ Good	Reportable, filterable, feeds attribution analysis
Industry	Dropdown	✅ Good	Essential for segmentation and territory planning
Contract End Date	Date	✅ Good	Triggers renewal workflows, feeds forecasting
Employee Count	Number	✅ Good	Firmographic data from enrichment, feeds ICP scoring
Notes	Free text	⚠️ Okay	Use activities/notes instead — free text on contacts is rarely searched
Favorite Color	Text	❌ Bad	Not relevant to any business process
Initial Conversation Summary	Text	❌ Bad	Use an activity with notes — this will never be reported on
Complete Address	Text	❌ Bad	Use structured location (city, state) instead of one text blob

The Decision Framework

1.Will anyone filter or search by this field? → If no, use a tag or activity note instead.

2.Will this field appear in a report or dashboard? → If no, reconsider why it exists.

3.Can this be a dropdown or number instead of free text? → Always prefer structured types.

4.Will enrichment or API integrations populate this field? → Great — automated fields have highest adoption.

5.Will reps actually fill this in? → If manual and not enforced, adoption will be < 30%.

How crmzero handles this

crmzero supports custom fields on contacts and deals with types (text, number, date, dropdown). All custom fields are fully accessible via API — so enrichment pipelines and integrations can populate them automatically, driving adoption without relying on manual entry.

See the API docs →

Frequently Asked Questions

How many custom fields should a CRM have?

There's no magic number, but a good rule of thumb is 5-15 per object (contacts, deals). More than 20 and you're likely creating clutter. Audit quarterly and remove fields with < 30% fill rate.

Should I use tags or custom fields?

Use custom fields for structured data you want to filter and report on (Industry, Lead Source, Contract Date). Use tags for ad-hoc, flexible grouping (event attendance, campaign membership). Tags are easier to add; custom fields are more powerful for analysis.

What's the best field type for custom data?

Dropdowns for anything with known options (Industry, Lead Source, Deal Type). Numbers for quantitative data (Employee Count, Revenue). Dates for time-based triggers (Contract End, Last Contacted). Free text only for truly unstructured data.

How do I get reps to fill in custom fields?

Three strategies: make them required at stage transitions, auto-populate through enrichment/API, and show reps how the data helps them (e.g., better pipeline views when Industry is filled). Mandatory + automated = high adoption.

CRM Foundations