Short Answer
You can purchase the Duolingo English Test up to 3 times within any rolling 30-day period. Each purchase gives you one credit, and each credit allows up to 3 attempts — but only one certified result counts per credit.
How the Credit System Actually Works
- Each purchase = 1 credit
- Each credit gives you up to 3 attempts to produce one certified result
- You have 21 days from purchase to use a credit before it expires
- You can buy a maximum of 3 credits in any 30-day window, counted on a rolling basis from each purchase date — not a fixed calendar month
Worked Example
Say you purchase your first test on August 1st. You could then purchase a second on August 3rd and a third on August 5th, using up all 3 credits for that 30-day window. You wouldn't be able to purchase a 4th test until August 31st — 30 days after your very first purchase — regardless of when you actually sat each test.
Does an Invalidated Test Count?
An invalidated or uncertified attempt still counts toward your 30-day purchase limit and uses up part of your credit, even though you don't receive a usable score from it. This is one of the biggest reasons it's worth getting your technical setup right the first time.
Do Universities See All My Attempts?
No. You choose which certified score to send, and institutions only see the result you send them — not how many times you took the test or what your other scores were.
Frequently Asked Questions
Is there a lifetime limit on how many times I can take the DET?
No — there's no overall cap, only the rolling 30-day purchase limit.
Do I have to wait for my results before retaking?
Yes, you generally need to receive your result from one attempt before scheduling another with a new credit.