Try this one. It might be helpful for you. It positions the text over the text input using absolute positioning.
.input-box {
position: relative;
}
input {
display: block;
border: 1px solid #d7d6d6;
background: #fff;
padding: 10px 10px 10px 20px;
width: 195px;
}
.unit {
position: absolute;
display: block;
left: 5px;
top: 10px;
z-index: 9;
}
<div class="input-box">
<input value="" autofocus="autofocus"/>
<span class="unit">£</span>
</div>