What a Teradata to BigQuery Migration Actually Costs in 2026

Ask five vendors for a Teradata-to-BigQuery migration quote and you'll get five very different numbers — not because anyone's lying, but because most quotes only price the part everyone can see: moving the data. The cost that actually determines your budget lives in the parts nobody puts in the initial estimate.

The five real cost drivers

1. Licensing overlap

You will pay for Teradata and BigQuery simultaneously for the length of your migration. This is the least surprising cost and the most consistently underbudgeted one — teams plan for a 3-month migration, it takes 5, and nobody adjusted the overlap line item.

2. Schema conversion — the easy 80%

Straightforward tables with standard data types convert fast, often with tooling assistance. This is the part most cost estimates focus on, because it's the easiest to scope.

3. BTEQ and stored procedure conversion — the expensive 20%

This is where budgets actually go. BTEQ scripts accumulate years of undocumented business logic — implicit casting, multi-statement transactions, sentinel date handling, macros calling macros. None of this shows up in a table count. A "5,000 table migration" and a "5,000 table migration where 800 tables are fed by BTEQ scripts with embedded business logic" are completely different projects, and the second one is where most fixed-bid vendors either lose money or cut corners.

4. Validation

Row counts matching is not validation. Real validation means reconciling aggregates, checking for silent type-conversion drift (a classic: BYTES fields that need explicit casting to BIGNUMERIC, not implicit casting that quietly truncates precision), and running the new and old systems in parallel long enough to catch discrepancies that only surface on specific dates or edge-case records. Budget for this as its own phase, not a checkbox at the end of migration.

5. Post-migration governance

The migration isn't done when the data lands in BigQuery. Cataloging, lineage documentation, and access controls that existed (even informally) in the old system need to be rebuilt — or you've traded a technical debt problem for a compliance one.

A rough shape of the budget

Every environment is different, but across engagements we consistently see the same shape: schema and straightforward table conversion is the smallest line item by effort, BTEQ/logic conversion and validation together are the largest, and governance is the one most likely to get cut when budgets tighten — which is exactly the wrong place to cut it.

Phase	Typical share of effort	Where estimates usually go wrong
Assess & inventory	5–10%	Skipped or rushed to save time upfront
Schema conversion	15–20%	Priced accurately most often
BTEQ / logic conversion	30–40%	Consistently underscoped
Migration & validation	25–30%	Treated as a formality, not a phase
Governance & cutover	10–15%	First thing cut under budget pressure

The one question that actually predicts your cost

Not "how many tables" — "how much of your business logic lives in BTEQ scripts instead of in an application layer?" A migration with clean, well-documented tables and minimal procedural logic can move fast even at large scale. A smaller platform with heavy BTEQ logic and undocumented dependencies will cost more per table, every time.

That's exactly what a proper assessment is for — scoring the real complexity before anyone commits to a number.