The phrase "a substantial client" is correct and usable in written English.
You can use it when referring to a client that contributes significantly to a business or organization, either in terms of revenue or importance.
Example: "Our agency has recently secured a substantial client, which will greatly enhance our portfolio."
Alternatives: "a major client" or "a significant client".
Specific objectives we will seek to meet over the next two years include: To build a substantial, regular client base of 100 clients on monthly cleaning plans, for a total of over 800,000 square feet of office cleaning each month.
Nick Lewis, head of market trading and risk at Capital Spreads, said: Today we have seen substantial client volumes buying into Royal Mail.
He's lucky he has substantial clients and they haven't gone bankrupt".
"We have several substantial clients that don't have Walgreen in their network at all," says a spokesperson.
Considerable progress toward a settlement, including a substantial transfer of client data, has been made.
The development, announced this week by the trustee tasked with returning money to MF Global customers, suggests that a substantial sum of client funds is still sitting at JMorgan.
The discussions, announced this week by the trustee assigned to return money to MF Global customers, suggest that a substantial sum of client funds is still sitting at JPMorgan.
The Goldman Sachs Group, Inc. is global investment banking, securities and investment management firm that provides a wide range of financial services to a substantial and diversified client base that includes corporations, financial institutions, governments and high-net-worth individuals.
At the onset of the downturn, we truly had a winning team -- dedicated, talented and supremely capable of managing a substantial workflow and client relationships.
"The Company is a global financial services firm providing investment banking, securities and investment management services to a substantial and diversified client base," Goldman wrote to the SEC.
