I have faced this challenge and have been helping startups and small companies to deal with it.

Large companies worry about your size as they know they will be delaying the payments and want to know if you can still run your operations.
Use the following numbers
1. No of collective years of experience your team has in stead of 10 member team
2. No of employees of your customer base to whom you serve / served. In stead of 20 customers, say that you have been serving a collective employee base of 2000 if avg employees of your customers is 100
3. Look at the largest number which can represent your work. If you are a housekeeping services company, talk about sqft which you cover today.

It is in human nature that when we hear big numbers which are credible, we don't question them. And you can always substantiate these number if challenged.

If you need to discuss this further, please feel free to discuss.
With warm wishes,
Sridhar