I would prefer to say ninety-nine hundred and ninety-nine thirty. Don't say "and". These numbers read differently than quantities. Otherwise, you could say nine thousand nine hundred. If you are talking to someone on the phone and it's important to be absolutely clear, then read the digits: nine nine zero zero.

Don't read it as a full "amount" - that's very tiring and confusing to listen to. If you have a sequence of numerals to read out (eg. a phone number or product code), you can: - use individual digits: nine-nine-zero-zero - group them: double-nine, double-zero (999 can be triple-nine, but for 0000, read double-zero, double-zero) - treat them as numbers less than a hundred: ninety-nine, thirty - round numbers can be read as a single number: 9900 can be ninety-nine hundred ...or any combination, such as "double-nine, thirty" for 9930. Make sure the listener reads it back to you, if possible.

I used to sell mobile phones over the phone when I used to work for the phone company. We had a phone called the 2125, and we always pronounced it as "The twenty-one twenty-five", I never heard anyone call it "the two one two five". We also had a Blackberry that was the 7100C. That we pronounced "seventy-one hundred C". Last, it's not 'two reads', it would be 'two different readings' 'two different ways to read it'

When I am reading product numbers over the phone to some one I usually say each number individually "nine nine zero zero" or "nine nine three zero" that is the clearest way to say the numbers.

It is commonplace to speak product numbers as individual numbers. However, when a product number between two and four digits in length, then it would be quick and easy to speak the product number in pairs. For example: 95746 would be "product number nine five seven four six." Here are some more examples: 9900 - ninety-nine hundred 9930 - ninety-nine thirty 9922 - ninety-nine twenty-two 8340 - eighty-three forty 830 - eight thirty 99304 - nine nine three zero four