The master guide

How to date a postcard

Work from the strongest evidence to the weakest, and stop when you're satisfied. The order below narrows fastest.

1. Read the postmark first

A legible cancel is the only evidence that gives an exact day, and it always sets the latest possible production date. Even a partial cancel — a readable year, a one-cent or two-cent stamp — bounds the card hard.

2. Look for a Curt Teich production number

If a small number like 6BH2667, A87976 or 6262-29 appears in a corner, your card was printed by the largest postcard house in the world, and the number encodes its date. The decoder reads it against the Curt Teich Archives' tables — often to the exact year.

3. Run the dots test

Under a magnifier (or a zoomed phone photo): tiny printed dots mean a printed card — go to step 4. Smooth continuous tone means an actual photograph — a real photo postcard — and its date lives in the stamp box on the back, where the paper brand and corner marks carry known production windows.

4. Read the back, the border, the surface

For printed cards, three physical questions place the era: is the back divided (US cards: divided from March 1907)? Is there a white border (1915–1930)? Is the stock woven like linen (1930–1945) or glossy like a photograph (1945 on)? The wizard asks these in order; the era guides go deeper on each.

5. Use the small print

“Private Mailing Card” bounds a card to 1898–1901. “Printed in Germany” on a divided-back card means almost certainly before 1915, when the war ended the German printing trade. A publisher's name bounds dates too — a card cannot predate its publisher — which is where our publisher pages are headed next.

Two honest rules

Every visual signal is a range, not a date; only postmarks and Teich numbers give you a year. And when the references behind a range disagree, we show the disagreement — see sources & methodology — because a confident wrong answer is worse than an honest range.