Misplaced alignment tab character &

What it means

TeX found an & where no table or alignment is open. In LaTeX the bare & is reserved for separating columns in tabular, align, the matrix environments and similar. Anywhere else it is an error, and TeX leaves the character out of the PDF. If you wanted an ampersand in the text, type \&.

The log line

This small file triggers the error:

\documentclass{article}
\begin{document}
This follows Smith & Jones (2024).
\end{document}

Compiled with pdfLaTeX (TeX Live 2026), it writes this to the .log file:

! Misplaced alignment tab character &.
l.3 This follows Smith &
                         Jones (2024).
I can't figure out why you would want to use a tab mark
here. If you just want an ampersand, the remedy is
simple: Just type `I\&' now. But if some right brace
up above has ended a previous alignment prematurely,
you're probably due for more error messages, and you
might try typing `S' now just to see what is salvageable.

The l.3 line breaks right after the offending &, the one between Smith and Jones. TeX's help text gives the remedy itself: type \&.

To try a fix without touching your project, save the example as a .tex file and compile it online with the LaTeX to PDF tool.

Why it happens

The causes below are in order of likelihood. Each has a before and an after you can compare with your own source.

1. An ampersand in running text, a heading or a caption

Company names, author pairs and section titles are the usual places.

Before

\section{Mergers & acquisitions}

After

\section{Mergers \& acquisitions}

2. An & in an environment that does not align

equation sets one formula and has no columns. To line up equals signs, use align, or aligned inside an equation, both from amsmath.

Before

\begin{equation}
y &= ax + b

After

\begin{align}
y &= ax + b

3. A URL with a query string

Web addresses use & between parameters. Put the address in \url{...} from the url or hyperref package, which accepts it as typed.

Before

See https://example.org/search?q=latex&page=2 for the list.

After

See \url{https://example.org/search?q=latex&page=2} for the list.

4. An & in a .bib field

A journal or publisher name with an ampersand passes through BibTeX unchanged and fails when LaTeX reads the .bbl file. The log then shows a .bbl line such as \newblock {\em Science &. Fix the .bib file and run BibTeX again.

Before

journal = {Science & Society},

After

journal = {Science \& Society},

How to find the line

The l. line is exact when the & is in your own text. When the last file opened in the log is a .bbl file, the ampersand is in your bibliography: find the entry by the words around the break and correct the .bib file, not the .bbl, which is rewritten on every BibTeX run. If the & is inside what should be a table, something above it closed the table early.

When you run pdflatex in a terminal without -interaction=nonstopmode, TeX stops at the error and prints a ? prompt. Press Return to carry on past the error, type x to quit, or type h for TeX's own help text, which is the paragraph you see after the l. line in the log. Editors run TeX in non-stop mode, so you get the log and never see the prompt.

What each editor shows:

• ModernTex: when a build fails, the Build button shows the error count and the last good PDF stays on screen. The Build Results panel lists each error, warning and note in plain language, Compile › Next Issue steps through them, and Raw Log shows the full LaTeX log. See ModernTex.
• Overleaf: the logs panel, opened with the button next to Recompile, lists each error and warning with its file and line, and the editor marks the line in the gutter. The unprocessed log is at the bottom of that panel.
• TeXShop: the console window shows the log as it is written and stops at the error. Goto Error moves the source window to the line. TeXShop's default pdfLaTeX command includes --file-line-error, so the same error starts with the file and line in place of the !: ./main.tex:3: Misplaced alignment tab character &.

Related errors

• Extra alignment tab has been changed to \cr: too many & inside a table.
• Missing $ inserted: the matching error for _ and ^ in text.
• Citation `x' undefined: the other common problem that starts in the .bib file.