What's the Thai phrase for "Keep the change" allowing someone to keep the change of a transaction as a tip?

"Mai pen lai"

(You can say "mai dtong tawn")

13 minutes ago, Lorry said:

"Mai pen lai"

(You can say "mai dtong tawn")

Do you know that in Thai? 

ไม่เป็นไร

(You can say ไม่ต้องทอน)

You wrote it correctly in Thai Lorry but pronounce it wrong Mai Pen Rye, it is an R sound Rah Rua, not an L sound Law Ling, very common Thai mistake. 

1 hour ago, marin said:

You wrote it correctly in Thai Lorry but pronounce it wrong Mai Pen Rye, it is an R sound Rah Rua, not an L sound Law Ling, very common Thai mistake. 

I know this

I wrote it how it is pronounced in Bangkok,  in common speech, by ordinary people who don't show off

A newscaster would pronounce a nice rolling r, and some people from Burrirram (I know it's spelt differently) or from the south, too

 

I thought - maybe erroneously - OP doesn't know much Thai,  so it would be better for him to learn what he actually hears others saying

 

 

5 minutes ago, Lorry said:

by ordinary people who don't show off

They are taught it in school, I dont think it has to do with showing off but how, and how long you were educated. 

mai tong tawn seems most understood.

3 minutes ago, marin said:

They are taught it in school, I dont think it has to do with showing off but how, and how long you were educated. 

I said ordinary people. 

Ordinary Thais do not have a postdoctoral degree in advanced physics. 

 

People with a BA have learned to roll their r, and do it at special occasions (like deliberately, slowly pronouncing a word to teach a foreigner). 

 

2 minutes ago, mokwit said:

mai tong tawn seems most understood.

Yes.

Depends a bit on the context. 

You pay a taxi, he starts searching in his purse for coins,  you just say ไม่เป็นไร.

 

mai tong tawn is always good, because it literally means "no need for change"

I 

2 minutes ago, Lorry said:

Ordinary Thais do not have a postdoctoral degree in advanced physics. 

 

Dont take it so far. I have taught in the Thai university system for over 35 years. Very few students pronounce R as L is a fact. But if I am travelling and staying in medium accommodation or eating in roadside restaurants most use the L for R.  It does not have to do with a higher degree at all. I have never heard my wife use the L for R sound, yet my housekeeper never uses the R sound and always the L. 

Have a good one.