Guides · Fax numbers

TSP fax number (Thrift Savings Plan)

Checked against tsp.gov on November 11, 2026

Fax TSP forms to 1-276-926-8948. That’s the number on the TSP’s contact page now; many sites still show the old 1-866-817-5023. If the form you’re sending prints its own fax number, use that.

Fax numbers

How to fax it

  1. Fill in the TSP form and sign it.
  2. Include your name and TSP account number.
  3. Send it from dimefax.com/send.
  4. Keep the delivered confirmation. Dimefax shows the date and time it went through.

Tips

Dimefax costs 10¢ a page and you’re only charged if the fax goes through. On the web, page credits come in packs of 50 for $4.99, 100 for $9.99 or 200 for $19.99; the Dimefax iPhone app also sells 10 for $0.99. Credits you don’t use stay in your account and last as long as you fax once a year.

Where these numbers come from

Dimefax isn’t part of, or endorsed by, the Thrift Savings Plan. We copied these numbers from tsp.gov on November 11, 2026. Agencies change their numbers: if your letter, notice or form gives a different one, use that.

Questions

What is the TSP fax number?

1-276-926-8948.

Is 1-866-817-5023 still the TSP fax?

The TSP’s current contact page lists 1-276-926-8948 instead.