How do I get the TER of an ETF or fund by ISIN?

Where it is in the response

Sample for iShares Core MSCI World UCITS ETF (IE00B4L5Y983):

json
"headlineMetrics": { "ter": "0.20%", "aum": "USD 151.7bn", "volatility3y": "11.8%", "sharpe3y": "1.68" },
"costs": { "entry": "0.00%", "exit": "0.00%", "ongoing": "0.20%", "transaction": "0.01%", "performanceFee": "0.00%", "riy1y": "0.21%", "riyRhp": "0.21%", "recommendedHoldingPeriod": "5 years" }

Where the figure comes from

The TER is read from the fund's own factsheet or product page; the KID cost table gives the fuller PRIIPs breakdown (entry, exit, ongoing, transaction and performance fees, and the reduction in yield). Both are returned as the fund house prints them, so a fund quoting "ongoing charges" rather than "TER" still lands in headlineMetrics.ter.

The request

bash
curl -s --max-time 300 https://fundfactsapi.com/api/v1/funds/IE00B4L5Y983 \
  -H "Authorization: Bearer $FUNDFACTS_API_KEY" | jq '.data.headlineMetrics.ter'

python
import os, requests
r = requests.get("https://fundfactsapi.com/api/v1/funds/IE00B4L5Y983",
                 headers={"Authorization": f"Bearer {os.environ['FUNDFACTS_API_KEY']}"}, timeout=300)
fund = r.json()
print(fund["name"], fund['data']['headlineMetrics']['ter'])

javascript
const res = await fetch("https://fundfactsapi.com/api/v1/funds/IE00B4L5Y983", {
  headers: { Authorization: `Bearer ${process.env.FUNDFACTS_API_KEY}` },
  signal: AbortSignal.timeout(300_000),
});
const fund = await res.json();
console.log(fund.name, fund.data.headlineMetrics.ter);

Sign up at fundfactsapi.com/signup for a key; the Free plan is 15 lookups a month with no card. Without a key, GET https://fundfactsapi.com/api/v1/demo/funds/IE00B4L5Y983 returns the same payload for funds already in the store (30 calls a minute per IP; it never loads a new fund).

Caveats

• TER and ongoing charges are close but not identical; the factsheet figure is what most comparison sites show, the KID figure is what regulation requires. Both are in the payload.
• The figure is a string ("0.20%") so that what you display matches the document. Strip the percent sign and cast when sorting or averaging; POST /portfolio already computes a weighted TER for a list of positions.
• Share classes of the same fund often carry different TERs. Look up the exact ISIN your client holds.

Several funds at once

POST /funds with { "isins": ["…", "…"], "wait": true } returns the same payload for up to 10 ISINs per call on Starter, 50 on Pro and 200 on Scale. One request is counted per ISIN answered. X-RateLimit-Remaining on every response tells you how many are left this month; a 429 rate_limited response carries Retry-After. Search and /me are free.

A fund nobody has requested in the last 24 hours is loaded on demand from the documents the fund house publishes. That first call takes 15 seconds to about 3 minutes; set your client timeout to 300 seconds and do not fire a second request for the same ISIN while the first is running. Every later call within 24 hours returns from the store in well under a second with cached: true.

Everything else in the payload is listed in the field reference.