How do I plan a credit budget for a large one-off campaign?

A one-off campaign with a 200,000-address list, a 1.2M-address list, or anything in between is a budgeting question with a clean answer in Valid Email Checker. Buy a PAYG tier that covers the deduplicated address count plus a small buffer, and let the credits sit until the work is done.

Step 1: count unique addresses

The number on your CSV is not your budget. Bulk Upload deduplicates automatically by default. A 250,000-row CSV with 12% duplicates becomes a 220,000-row job. Pre-counting unique addresses in your source data (one column-uniq pass in Excel or SELECT COUNT(DISTINCT email) in SQL) gives the actual credit need. See how bulk upload deduplicates.

Step 2: add a small buffer

Add 5% to the unique count to cover:

• Addresses you might add late (last-minute imports from a different system).
• Retries of unknown results on day two (Unknown auto-refunds, but the retry charges).
• A small unrelated verification need (single-email checks via the dashboard) during the same period.

A 220,000-address campaign becomes a 230,000-credit budget. Round up to the next PAYG tier so you do not run out mid-job.

Step 3: pick the tier that minimizes per-credit cost

Valid Email Checker's PAYG pricing is tiered with bonus credits at higher tiers. The largest tier has the highest bonus and the lowest effective per-credit cost. For a 230,000-credit campaign, buy whichever tier covers it in a single purchase — splitting across multiple smaller tiers usually means a worse per-credit rate. See how to choose between PAYG tiers for the specific math and the largest PAYG bonus tier for the headline rate.

Step 4: PAYG vs Monthly for one-offs

For a true one-off campaign with no follow-up volume planned, PAYG wins. PAYG credits never expire — leftover credits from the one-off campaign sit there indefinitely and cover future single-email checks or smaller follow-up jobs. Monthly plans reset every billing cycle, so a Monthly subscription bought for a single big campaign would lose unused credits at the next renewal.

If the "one-off" is the first of an expected steady stream of campaigns, see when should I switch from PAYG to Monthly for the cross-over math.

Step 5: do not over-engineer the buffer

5% is enough. We've seen teams add 30 to 50% buffer out of caution, which is wasted purchase. Even if the buffer is undersized, you can buy a top-up tier mid-campaign at any time — the dashboard accepts a fresh PAYG purchase even while a bulk job is running, and the new credits land before the job needs them.