Vanguard is stepping up its efforts to push users of its mutual fund-only platform to its brokerage service with a new fee charge on every fund, according to news reports.

Mutual fund-only customers will need to pay an annual $20 fee per fund starting in September, FA-IQ sister publication Ignites writes, citing Vanguard’s website.

That’s on top of the $20 annual account fee, according to the publication.

While clients can avoid the account fee by going paperless or meeting other standards, the same option doesn’t extend to the per-fund fee, Ignites writes, citing the disclosure.

People posting on the Bogleheads online message board believe the fee is Vanguard’s latest attempt to get people off the mutual fund-only platform, according to the publication.

The firm has been trying to encourage investors to switch to its brokerage service for years, Dan Wiener, chairman of Adviser Investments and editor of the Independent Adviser for Vanguard Investors, wrote in an email to subscribers earlier this week, according to Ignites.

Last week, Vanguard sent an email to clients saying that it’s “working to retire that platform so we can better serve all clients with a more modern, personalized investing experience,” according to Vanguard investors on the Bogleheads message board, the publication writes.

The email also notes the new fee and adds that users who chose to remain on the fund-only platform “may lose certain features and functionality over time,” according to Ignites.

Vanguard clients on the hybrid robo Personal Advisor Services — which has a $50,000 threshold for avoiding account fees — and the $3,000-minimum Digital Advisor, are exempt from the per-fund fees, the publication writes, citing the disclosure.