If your biggest customers left, how much would you lose? Enter three numbers from last year and see how much of your revenue rests on a handful of people.
Your 10 biggest customers are the ten people or businesses who spent the most with you. Your sales report or customer list can sort them. Example numbers are made up.
The link holds your numbers. The card is a paper-ground PNG of the verdict.
Plain version: divide the revenue from your 10 biggest customers by everything you sold. The bigger that share, the more you depend on a few people.
Use one full year. A single month can make a regular buyer look like a big one, or a one-off look like a loyal customer.
Use net revenue. Refunds should come off the top customers before you add them up.
There is no good or bad percentage. Some businesses should depend on a few big accounts. The question is whether you know who they are and are looking after them.