Understanding MT 700 Fields 39A and 39B – Amount Tolerance Explained

Intro

In SWIFT MT 700, Fields 39A and 39B are often referred to as “tolerance Fields”. Although both relate to the credit amount, they serve different purposes and lead to very different practical outcomes. This Q&A explains the distinction and when each Field is typically used.

Question

Dear Sir,

Good day!

I have some doubts on Tolerance Field39A and 39B.

Could you please provide an explanation about the difference between Field39A and Field39B.

Regards,

Nishanth

_______

Answer

Dear Nishanth,

Thank you for your question.

Fields 39A and 39B are optional fields in SWIFT MT 700. They both relate exclusively to the credit amount, but they operate in very different ways. Only one of these fields may be used, not both.

Field 39A – Percentage Credit Amount Tolerance

Field39A is used to specify an allowed tolerance above and/or below the credit amount, expressed as a percentage.

When words such as “about” or “approximately” are used in connection with the amount of the credit, UCP 600 Article 30(a) allows a tolerance not exceeding 10% more or 10% less than the stated amount.

Example (SWIFT code):

:39A: 10/10

This means the credit amount may vary by +10% or −10%.

Field 39A therefore introduces controlled flexibility in the credit amount.

Field 39B – Maximum Credit Amount

Field 39B is used to qualify the credit amount by setting a firm maximum, most commonly by using the code “NOT EXCEEDING.”

Example (SWIFT code):

:39B: NOT EXCEEDING

This Field permits no upward tolerance beyond the stated credit amount.

In practice, 39B is often used in line with UCP 600 Article 30(c), particularly where freight and/or insurance are quoted in soft terms, typically under CFR or CIF Incoterms. Article 30(c) allows flexibility within invoice components but clearly requires that the amount drawn must not exceed the credit amount. Field39B reinforces this strict cap.

I hope this clarifies the difference between Fields 39A and 39B.

Best regards,

Mr. Old Man