Looking at the Thai consulate website tourist visa section and it's asking for photos to be 2" by 2".
How to Apply for a Visa by Post

 

Passport photos are 45 millimeters (mm) high by 35mm wide.

 

Has anyone had any problems with sending in normal passport size photos for a visa application?

 

I've just read another section on the above link.

 

Near the bottom of the page under title

When Submitting your Application by Post

 

Which says to send in "Two (2) recent passport size photos."

 

More confused now as I don't want send my Passport and application in only to have it rejected.

 

TIA 

What size does the visa application form ask for. If not get some 2 X 2 inch photos to use.

The 2" X 2" is the standard passport size in many countries. A few do use 3.5 X 4.5 cm photos now.

You do not mention which consulate. The size and number (one or two) varies, as does how strict they are about having them the correct size.

20 minutes ago, BritTim said:

You do not mention which consulate. The size and number (one or two) varies, as does how strict they are about having them the correct size.

Thai Embassy, London, UK

(from the link in OP)

Thanks to all for taking the time to reply