Dynamics 365 native import limits, explained

The Dynamics 365 import wizard covers the simple case. But when the file grows or the data comes in imperfect, there are limits documented by Microsoft that are worth knowing before the import, not during it.

The limits, in a table

Limit	Documented value	What it means in practice
Rows per import	Recommended: 20,000 or fewer	A typical contact migration (40,000 to 100,000) forces you to split the file into several manual imports.
File size	8 MB (32 MB as .zip)	An Excel file with many columns hits the limit well before 20,000 rows.
Duplicate rules	Maximum 5 published per table	Real scenarios (email, phone, company name, domain, tax ID…) quickly exceed 5 rules.
Record merge	Only Account, Contact and Lead · 2 records at a time	Cleaning up 500 duplicates means hundreds of manual merges, in pairs.
Error messages	Per record, with no file context	The classic “row failed” without knowing which column or why. You fix blindly, retry, repeat.
Unsupported fields	Owner, multiselect, file/image in the modern Excel import	Records come in with no owner assigned, or the field simply can’t be mapped.

Limit

Documented value

What it means in practice

Rows per import

Recommended: 20,000 or fewer

A typical contact migration (40,000 to 100,000) forces you to split the file into several manual imports.

File size

8 MB (32 MB as .zip)

An Excel file with many columns hits the limit well before 20,000 rows.

Duplicate rules

Maximum 5 published per table

Real scenarios (email, phone, company name, domain, tax ID…) quickly exceed 5 rules.

Record merge

Only Account, Contact and Lead · 2 records at a time

Cleaning up 500 duplicates means hundreds of manual merges, in pairs.

Error messages

Per record, with no file context

The classic “row failed” without knowing which column or why. You fix blindly, retry, repeat.

Unsupported fields

Owner, multiselect, file/image in the modern Excel import

Records come in with no owner assigned, or the field simply can’t be mapped.

Limits according to Microsoft’s official documentation (learn.microsoft.com) · June 2026

How ImportToD365 solves it

ImportToD365 was designed around these limits. You upload your full Excel or CSV and validation runs before touching the CRM: you see every error with its exact reason and fix it inline, without going back to Excel. Possible duplicates are compared side by side against your Dynamics records, without depending on the 5 native rules, and you approve case by case or in bulk. Only the records you approved are written, what already exists in your CRM is never modified, and at the end you download the row-by-row report.

You only pay for rows successfully written to Dynamics: invalid rows, rejected duplicates and discarded rows don’t use quota.