It can be written by migrant workers. According to the relevant information on the use of IOUs, it is known that as long as all parties have true intentions, reach consensus through consultation, and do not violate relevant mandatory legal provisions, any written signature by one of the two parties will be valid. Writing an IOU with specific legal effect should include the following items:

1. The debtor must handwrite the IOU, but it must be written in a standardized manner. Printed IOUs are also legally binding, but can be easily forged.

2. Write clearly the date when the debt occurred, and be accurate to the day.

3. The amount owed must be written in both uppercase and lowercase letters, and the currency must be clearly stated.

4. The debtor is married, and the signature of the spouse is required.

5. Also collect copies of ID cards and marriage certificates signed by the borrower.