We consider homeomorphisms  $f,h$ generating a faithful
$f,h$ generating a faithful  $\mathit{BS}(1,n)$-action on a closed surface
$\mathit{BS}(1,n)$-action on a closed surface  $S$, that is,
$S$, that is,  $hfh^{-1}=f^{n}$ for some
$hfh^{-1}=f^{n}$ for some  $n\geq 2$. According to Guelman and Liousse [Actions of Baumslag–Solitar groups on surfaces. Discrete Contin. Dyn. Syst. A 5 (2013), 1945–1964], after replacing
$n\geq 2$. According to Guelman and Liousse [Actions of Baumslag–Solitar groups on surfaces. Discrete Contin. Dyn. Syst. A 5 (2013), 1945–1964], after replacing  $f$ by a suitable iterate if necessary, we can assume that there exists a minimal set
$f$ by a suitable iterate if necessary, we can assume that there exists a minimal set  $\unicode[STIX]{x1D6EC}$ of the action, included in
$\unicode[STIX]{x1D6EC}$ of the action, included in  $\text{Fix}(f)$. Here, we suppose that
$\text{Fix}(f)$. Here, we suppose that  $f$ and
$f$ and  $h$ are
$h$ are  $C^{1}$ in a neighborhood of
$C^{1}$ in a neighborhood of  $\unicode[STIX]{x1D6EC}$ and any point
$\unicode[STIX]{x1D6EC}$ and any point  $x\in \unicode[STIX]{x1D6EC}$ admits an
$x\in \unicode[STIX]{x1D6EC}$ admits an  $h$-unstable manifold
$h$-unstable manifold  $W^{u}(x)$. Using Bonatti’s techniques, we prove that either there exists an integer
$W^{u}(x)$. Using Bonatti’s techniques, we prove that either there exists an integer  $N$ such that
$N$ such that  $W^{u}(x)$ is included in
$W^{u}(x)$ is included in  $\text{Fix}(f^{N})$ or there is a lower bound for the norm of the differential of
$\text{Fix}(f^{N})$ or there is a lower bound for the norm of the differential of  $h$ depending only on
$h$ depending only on  $n$ and the Riemannian metric on
$n$ and the Riemannian metric on  $S$. Combining the last statement with a result of Alonso, Guelman and Xavier [Actions of solvable Baumslag–Solitar groups on surfaces with (pseudo)-Anosov elements. Discrete Contin. Dyn. Syst. to appear], we show that any faithful action of
$S$. Combining the last statement with a result of Alonso, Guelman and Xavier [Actions of solvable Baumslag–Solitar groups on surfaces with (pseudo)-Anosov elements. Discrete Contin. Dyn. Syst. to appear], we show that any faithful action of  $\mathit{BS}(1,n)$ on
$\mathit{BS}(1,n)$ on  $S$ with
$S$ with  $h$ a pseudo-Anosov homeomorphism has a finite orbit containing singularities of
$h$ a pseudo-Anosov homeomorphism has a finite orbit containing singularities of  $h$; moreover, if
$h$; moreover, if  $f$ is isotopic to the identity, it is entirely contained in the singular set of
$f$ is isotopic to the identity, it is entirely contained in the singular set of  $h$. As a consequence, there is no faithful
$h$. As a consequence, there is no faithful  $C^{1}$-action of
$C^{1}$-action of  $\mathit{BS}(1,n)$ on the torus with
$\mathit{BS}(1,n)$ on the torus with  $h$ Anosov.
$h$ Anosov.